Suppose I see that Book X is cited by several papers with reference to some particular Fact Y. I wish to cite Fact Y. As far as I know, Book X is the only reference for Fact Y.

I have never looked at Book X. Nonetheless, I cite it like this:

'Fact Y' (see Book X)

My question is: Is this ethical, given that I've never looked at Book X?

More context for my question. I am NOT asking whether this is good scientific practice. I am NOT asking how a good scientist should actually go about citing Fact Y. I am NOT asking if this could undermine your credibility as a scientist.

Instead, I am asking this question because it seems to be a somewhat-common practice. And moreover, as far as I know, no scientist has ever been issued even an official rebuke (much less fired) for engaging in such practice. This would suggest to me that this practice is not considered to be unethical.

Of course, it is not binary as to whether a practice is unethical. But I would simply like to know whether the academic community in general considers this to be even a mildly unethical practice. Or if it is perhaps very slightly unethical, but not a big deal. Or if it is not in the least bit unethical.

  • 5
    @scrappedcola: I don't understand what the relevance of your question is. But my answer to your question would be "no".
    – user10885
    Commented May 12, 2015 at 15:05
  • 6
    You may find the following question helpful: Do you need to read a whole article before citing it?
    – Mad Jack
    Commented May 12, 2015 at 15:07
  • 3
    Wikipedia is a source of secondary information that there is no guarantee of verified authenticity. All you have is a guess that book X mentions fact Y, without actually doing your homework that it is true. Are you willing to base your reputation on an unverified "fact" that may be completely out of context or incorrect? Commented May 12, 2015 at 15:07
  • 8
    An early draft of my thesis had a bit along the lines of "... X et. al are often cited as the originators of fact Y ..." while I tried to get hold of a fifty year old paper. With a footnote rather than a bibliographic entry giving the particulars of the publication. No idea if that dodge would have gotten past the margin lady, but it felt more honest to me. Commented May 12, 2015 at 15:57
  • 2
    Some good reading on the various issues with citing-via-other-papers (and the problem that there is often no perfect way to do it): Rekdal 2014, "Academic urban legends" sss.sagepub.com/content/44/4/638.full.pdf+html Commented May 13, 2015 at 12:54

11 Answers 11


When you cite a source, you are not actually claiming that you have read it. What you are actually doing is staking your professional reputation on that source containing the information that you claim that it contains.

In most circumstances, of course, this gets instantiated exactly how you would expect: at least one of the authors has personally read the source. There are, however, certain circumstances in which citation of an unread source is actually appropriate. Let me give two examples:

  • The source is cited as a secondary source, e.g., "Feng et al.[17] claim that the species presented in the Necronomicon[18] can be found in Antarctica." Here is is appropriate to give the bibliographic "pointer" to the secondary source even if you cannot access it yourself.
  • The source material may be known by a different route than the original publication. This frequently happens with software tools and standards: for example, you might cite a standard that you are using even if you haven't read the standards document. Likewise, if I am using a software tool, the authors often point to a particular paper as the preferred appropriate citation for the tool, and I am happy to take their word for it without reading that paper.

There may be many more cases as well. It all comes down to this: how certain are you that you really know that the document you cite serves the purpose for which you are citing it?

  • 28
    I think there are two occasions where I needed to cite mathematical results which were originally published in Russian, which I don't speak, but where the authors had later written about the work in English. I cited both, indicating that I had only read the English paper but that the authors said they were translating their work. I think this is pretty reasonable. Commented May 12, 2015 at 18:47
  • 2
    @jakebeal I think this is a very good answer, but am wondering what your take would be on the situation where the secondary source is a personal communication between the primary source and some other party? I actually have this as an AcademiaSE question entitled "Citing a Work that Cites a Personal Communication". If you'd be willing to adapt/extend your answer to that situation and submit as an answer, I'd be grateful to have it. Thanks!
    – iwantmyphd
    Commented May 13, 2015 at 13:53
  • If you are referring to this question, then I think my answer to it already covers the situation. Is there something else that you are looking to understand there?
    – jakebeal
    Commented May 13, 2015 at 14:44
  • @jakebeal Very odd... up until now, your answer wasn't showing up... thanks for mentioning it. Now having read it, I'd suggest either linking to your answer to the present question as this version goes into a bit more detail, or copy/pasting some of what is written here in your answer to my question. Either way, I appreciate it. Thanks!
    – iwantmyphd
    Commented May 13, 2015 at 18:37

(This is largely a response prompted by your addendum 2)

I'm not asking if such practice is a good idea or good scientific practice. (One comment and one answer seem to be saying that it is not good scientific practice. Which I agree with.) Instead, I'm asking if it is viewed among academics as unethical. (And to what degree: Is it no big deal? Or something to be deeply ashamed of if you're caught?)

Everyone agrees that it is neither a good idea nor a good practice, for reasons pointed out in the other answers. So, let's leave that out and focus on the crux of your question.

Is it unethical?

Yes. It is. More generally, claiming anything to be true when you are not too sure is unethical in the strict sense.

... something to be deeply ashamed of if you're caught?

Absolutely (i.e. if you are caught). Reputation (or disrepute) spreads. Or even if it doesn't, at least the people who catch you will always be skeptical of your claims, even when you are right. These seemingly innocuous, freak mistakes can easily blemish the reputation you earn the hard-way, by working very hard. Irrespective of how you try to sell it (upon being caught), it does count as unethical and is bound to leave you red-faced.

A big part of being successful and renowned in academia is earning respect and credibility through work. This question is best answered by asking yourself - Would I believe the claims of someone whom I've caught doing this?

PS - I'm sorry, I'm being the ethics police here. Other answers are claiming that this is harmless and won't cost you your job. I agree it won't, but it will cost you credibility and respect. If you repeatedly stress that your question is Is it ethical, I'm afraid, someone will have to stress that it really is not ethical. :)

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    As mentioned, this seems to me a common practice. (Feel free to disagree.) Yet to my knowledge, no one has ever been left "red-faced". (But perhaps you can give me some examples of persons who have been thus embarrassed.) Why has no one (or few) ever been left "red-faced"? Is it because (a) it is difficult to conclusively prove that someone engaged in this practice; or (b) it really isn't a big deal? My feeling is that it is more (b) than (a).
    – user10885
    Commented May 12, 2015 at 19:39
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    @KennyLJ - (Part 1, Example) - I had the privilege of embarrassing my own advisor and a group senior in this manner. They had been citing a book as the source of a parameter input in 3-4 of their papers. My intentions weren't bad, I only told them in a group meeting (only 3 of us) that I was looking for it, but I couldn't find that source anywhere, so I requested them to hand it to me since they must be having it. They were both clearly embarrassed while disclosing that none of them had seen it. Some other source had mentioned it and they followed suite. (ofc, it came back to bite me later)
    – 299792458
    Commented May 12, 2015 at 20:00
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    @TheDarkSide my issue is with conflating the 2 without establishing that in this case both actually apply.Taking up wearing a crown made of toilet roll tubes to all academic events may may you less credible but it's not unethical in any way. "Would I believe the claims of someone whom I've caught doing this?" has nothing to do with ethics as a measure. only credibility. Citing a source you haven't read with a claim about what it says may be somewhat unethical because it can propagate errors and false claims and it could also make the person less credible but one does not imply the other.
    – Murphy
    Commented May 13, 2015 at 15:08
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    this seems to me a common practice — Indeed, but many common practices are unethical.
    – JeffE
    Commented May 13, 2015 at 15:26
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    Suppose paper A, which I've actually read, proves Z and uses "when X holds, then Y [1]". Now, let's suppose I need the claim for my paper B, as part of my argument, and also Z. I have to write "when X holds, then Y". Then, should I point to A, which I cite elsewhere for Z, or to 1? I'd go for 1, and I think it would be misleading to point to A (you go to A, just to discover it does not "prove" the claim, but cite 1...). Nonetheless, it'd be better to add a clue for the fact you're "citing a citation"; if you don't, anyway, I can't see any ethical issue. Commented May 14, 2015 at 8:44

Think of the case when you are the author of the paper that wasn't read. A paper I had written was cited, but the authors only quoted a counterargument I had used, not the main conclusion of my paper. They then went on to argue that I was wrong, but reached the very same conclusion that I had presented later in my paper, but claimed theirs as a new result. Whether technically unethical or not, how do you think I feel about the authors and their paper? I certainly wouldn't be likely to collaborate with them or recommend their work, for fear of having my own work stolen or again misrepresented. As others have pointed out, their reputation, as far as I'm concerned, is gone.


If not unethical, I would certainly say unwise, since you are unable to find the context surrounding the statement of fact or answer that you want to reference. To clear yourself of this, you would have to mention that the text X is unattainable and that it mentions fact Y as useful, but that you would need further review of the material to verify the complete veracity of the statement as it applies to your specific usage of that fact. In other words, if you have bias in your presentation, acknowledge it clearly and don't hide it.

In answer to your specific question of how ethical this practice is...

I would say that it is unethical. The lesser transgression of ethics would be simply that the article would be using another person's work to pad the robustness of the bibliography. This is a minor point. The greater transgression brings me back to my earlier point of referencing a fact without context, which puts you in a questionable position when someone asks you for more information about that fact. Worse still would be to base one of your key thesis arguments on a fact from a text you couldn't find.

I understand that you are not actually doing this, so am only using 'you' for the purposes of conversation.


You make statements that you believe are true, e.g. citing a source for a fact. If you cite that source incorrectly - you fully believed that source corroborated your fact, but you were in error - you did poor work, but you did it ethically. If you can do more work to verify your source, but you do not, or you represent that you have done more work to verify your source that you have not done, then it doesn't matter whether the source corroborates your fact or not, you have behaved unethically.

If you are completely honest about exactly the level of work you have done to verify that the cited source corroborates your fact, you are in danger of being proven wrong, or of being dismissed as not having done the appropriate level of verification, but you have behaved ethically.

It's situational, in general it's probably poor practice but if you as the reader are aware of this situation then I'd say the author has at least behaved ethically.


This is often known as an 'indirect source' or 'secondary source'. Check the citation standards for your community, as there may be a specific style that should be used for these cases. In some styles you list only the secondary source in your reference list (with original mentioned in the text), in others you list both the original and secondary source as seperate items, and in others you have a sort of merged reference entry.

Note that you should only use this case if you either can't obtain the original (check with your library; they can make requests through inter-library loan, but this doesn't work if it's something that was never publihed), or you can't read the original because it's in a language that you don't undertand.

Here are libguides from various institutions that cover some common styles:

  • AMA & APA : use the phrase "as cited in", cite the secondary source.
  • Chicago : use "cited in" or "quoted in", cite the secondary source
  • MLA : use "qtd. in", cite the secondary source
  • Turabian : merged reference (Original. Cited in Secondary)

The devil is always in the details, but it can be perfectly ethical and professionally correct. There are several cases when it is almost inevitable: depending on your field, many equipment, software etc require to cite given references when you use them. These are technical citations that you may or may not read, and most of the times they have little useful information for you and you cite it to indicate to use the given method.

In e.g. chemistry typical examples are crystallography software, quantum chemical simulation software, visualization software, but I am sure you can find typical examples in many other fields.


It's less unethical than the circumstance you want to compare to without question. I don't think anyone has ever gotten fired citing something they didn't read, but it's possible for there to be a lot of trouble. Imagine the case where you cite a source for some fact which that source got from somewhere else. If you don't go check that they got it right, the entire validity of your article could come crashing down because you didn't bother to read enough sources. That's unlikely to cost you your job, but it could if the consequence of your article's invalidity are high enough.

  • @Kimball, yes. Ethics aren't binary. It's less bad to cite something you haven't read than it is to assault your student.
    – Bill Barth
    Commented May 13, 2015 at 2:29
  • Ah, I see, you were responding to the end of the first addendum.
    – Kimball
    Commented May 13, 2015 at 3:04

I think it’s not unethical in general, even if there could exist cases when the decision could be poor judgement, hence diminishing the credibility of the authors and trustworthiness of their work. But this is not about ethics.

As said in a comment, I don’t expect authors to have read all the cited works (each wholly, instead of partly, or indirectly…). In the same time, when I read a paper and find a specific claim with a reference, say, The fact Y holds [X], I expect X to be the paper or book supporting the statement. I am not really interested to know whether the authors have read X at all: I have only to know if X supports the claim or not.

Nonetheless, what if I read X and find that it is misquoted? Or if I discover that its results are misunderstood and that they do not support Y?

Since I don’t know whether the authors haven’t read X and they are instead trusting (wrongly) another source I can’t trace back (since they missed to provide me with the proper clue), their credibility crumbles in front of my eyes. In the same time, the citing paper loses all its supposed value.

Thus I can see only two reasons why authors should specify that the claim is supported in X and that “the claim is supported in X” is stated in a paper Z (and that this is how they know, or believe to know that Y is true):

  • to aknowledge authors of Z for their work (in fact, I suppose there’s a reason if the authors have read it);
  • to keep every link of the “chain of trust”.

In my opinion, only the former has something to do with ethics, while the latter has something to do with how scientific (and non-scientific) knowledge proceeds. I won’t elaborate on this “chain of trust”, but think about few things: If Z (containing the claim supported by X) was peer-reviewed, would you feel suspicious when you read The fact Y holds [X]? Would you act like a reviewer or just like a user assuming Z already proved to meet the necessary criteria to be considered trustworthy, in general and so in particular about that specific claim and the references? Would you instead go and check and verify all references, and then all the references contained in the referenced works, and so on? Would you stop at level 2, level 3, level 4 or level N before you think something is trustworthy enough? And if the paper is not peer-reviewed at all, what does it make trustworthy to you in first place?

When you decide to write The fact Y holds [X] and skip the link with your primary source, you are making a precise bold judgement: The link you are skipping is 100 % right, errors-free and nobody needs to check it (or even to know you relied on it). This is problematic for you, as an author, but not for any reader: You are not cheating “against” the reader, since to judge your work he only needs to know if X really supports Y (in turn, if the reader trusts you, he might decide you are not lying, unintentionally or not – another link in the chain), and you give him the reference, so he knows where to check for the claim. But, skipping the link Z, you bring on your shoulder the burden of anything Z does, mistakes included.

Therefore I agree with anybody saying it’s good practice to be accurate and let people (and reviewers) know The fact Y holds [X] is written in Z, and that this is your primary source for the claim. But I can’t see grounds to say that if you don’t, it is unethical – rather, it is simply in your own interests to do so.

In your case, there’s no Z, if I’ve understood correctly. It seems there’s something like a common knowledge, i.e., a collection of sources agreeing on the fact Y and suggesting (or stating) that the claim is supported by X. Your paper adds one more to this “cloud”, eventually growing the loop and a possible bubble — bad approach (especially if actually the author hasn’t picked one of those sources at all), but isn’t unethical to me.

(Let me say that if Y is something like James Watson and Francis Crick discovered the double helix structure of DNA and the book is The Double Helix: A personal Account of the Discovery of the Structure of DNA, I would not say that it is a bad approach. So, it might strongly depends on what we are actually talking about.)

I hope my answers, while touching already cited themes, adds few sparks to elaborate over the reason why it should, or should not be considered unethical the behaviour the OP describes.

  • 2
    +1 for a thoughtful, sophisticated, and detailed analysis.
    – Corvus
    Commented May 14, 2015 at 22:23
  • Your answer seems really good but I can't tell for sure because I'm having a hell of a time parsing your sentences. Any chance you could simplify them? For example, phrases like let people know "the fact Y holds [X]" is cited in Z is pretty complex and a bit confusing when every sentence reads like that.
    – user541686
    Commented May 15, 2015 at 0:12
  • @Mehrdad sorry... they seems clear to me, maybe I am trained to read sentences like that. I will think about a different way to say the same thing, but currently I can't come up with anything. I do accept reasonable suggestions. Commented May 15, 2015 at 6:06
  • @wrzlprmft I really don't get the meaning of your edits. Using quotes of one style or another does not matter, using italics instead of quotes neither; sentences like «the authors have read the X» are even less clear than «the authors have read the book X» (in fact, X is a book in the OP question). Since the book is just one (namely X), I could have said «the book» everywhere; though, I think (likely wrongly) having a label can be useful. Similar thoughts for paper C, which became Z. And «there's no Z» let a already confused reader wonder what that Z is... well, it's a paper, likely. Commented May 15, 2015 at 6:15
  • @ShinTakezou: 1) Guillemets (»«) are not used in the English language. 2) A label is useful, if some variable is used sparsely, which isn’t the case here. Who cannot remember what X, Y and Z are will be lost anyway, be they specified or not. Specifying them would be just another word to read. 3) paper C did not become Z, paper C was an unecessary placeholder; paper A became Z (to avoid confusion with the indefinite article).
    – Wrzlprmft
    Commented May 15, 2015 at 7:53

I am a Computer Science major and I have come across obvious instances of this in several of the journal articles I have read. Sometimes it seems ethically sound and sometimes it seems like the person was being lazy.

I agree with others that the key to remaining ethical is not presenting the information in an ambiguous way where a reader might think you have read the work when you have not. For instance, you have seen in book Z that book X is a reference to fact Y. I do not think it is then safe to say, "According to [book X], it has been shown that [fact Y]," but it is ethical to say "[Book Z] claims [fact Y], referencing [Book X]."

Whether this is effective enough in a paper is a matter of opinion I suppose, but I do think it is fair to say that it actually depends somewhat on the field. The more the research is based on experimental data, the more it seems like you would want to review the data yourself before citing it. However, if you are talking about what people are saying as opinion, academic, professional, or otherwise, you run less risk of making your paper less credible if you are clarifying that another author first made that interpretation of what that opinion might mean.


Yes, I think you can cite in a way that is ethically correct. If you claim c which is mentioned in book C, but you know this from book B which references C, you can cite:

AuthorC: "C", PlaceC, TimeC, cited in AuthorB: "B", PlaceB, TimeB.

even without ever holding book C in your hand. You delegate the responsibility for correctness of the information c to B.

See also: https://english.stackexchange.com/questions/148878/phrase-cited-after as well as http://www.reading.ac.uk/library/finding-info/guides/lib-citing-cited-ref.aspx

The phrases "cited in" and "cited by" are more common, albeit you may find "cited after" in some cases.

With regards to ethics, using the abovementioned method of citing you do avoid being dishonest and deceitful. However, the professor marking your scientific text may still think that you have cut a corner by not tracking down the actual source yourself.

Still hoping my answer helps,


  • 3
    Did you read the only answer of the question you linked? It says "... usually a no-go in serious academic writing (except, perhaps, in somy very exceptional circumstances, if you've cleared it with your academic advisor.) ...".
    – Nobody
    Commented May 13, 2015 at 11:49
  • 2
    You are not answering the question. The OP is asking whether it is unethical.
    – Nobody
    Commented May 13, 2015 at 12:44
  • @scaaahu That there is a correct form for doing this means that simply citing C is not the correct form, and could be viewed as unethical for concealing the fact that this was done. The "no-go" is actually doing this, not the citation form.
    – Random832
    Commented May 13, 2015 at 13:18
  • I've never seen the phrase "cited after" except here. Standard English would call for "cited by [author]" or "cited in [work]".
    – JeffE
    Commented May 13, 2015 at 15:23
  • @scaaahu Addressed your comments by my edits, but you need to put the "no-go" into the context in which it was written. This is about ethics and not whether your supervisor will be happy with your paper (and diligence to dig up sources). Sometimes the source will just not be available (e.g. very old texts, out of print) or in a language you do not understand. There is little choice then, except trust a reputable source to cite the information correctly, and honestly say upon which source you relied.
    – Ned64
    Commented May 14, 2015 at 0:42

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