I am writing a paper in math. In that paper, I need to quote several theorems/propositions from a classic textbook on the subject. All of them are quite standard results, but I am not sure what are the original sources for those. The book didn't say that either (unless it's a quite famous theorem, then it would have a name attached to it). How do I properly refer to that? I heard that if I don't put a name next to it, people will think I am claiming it, which I am not.

2 Answers 2


Contrary to intuition, it is often inappropriate to try to cite well-known and foundational material to its original source. The reason is that you did not actually learn the material in its original form but instead from some modern reinterpretation of that material (e.g., in a standard textbook).

To see why, try reading the original for something like Newton's Laws of Motion. First of all, it's in Latin. Even if you get a translation, however, you'll find that the notation is strange and difficult to comprehend. That is because even though the fundaments of Newtonian physics have not changed in the centuries since it was discovered, we have improved greatly in our ability to understand and teach the material, as well as in how we integrate it with other material.

In short: if it's textbook material, it is most honest to cite a textbook as your source. Two modifying notes, however:

  1. It doesn't have to be the textbook that you personally learned from---any good presentation will do.
  2. You only need to cite a textbook if some of your audience may be unfamiliar with the material. In a computer science paper, the halting problem needs no citation; in an interdisciplinary paper expected to be read by e.g., economists or biologists, it does need a citation.
  • Thanks! Any suggestions on how it should look like? Is it ok to not leave a name next to the theorem, and just say something like "here is a standard result from xyz book" below or after the theorem?
    – initial_D
    Jul 5, 2016 at 0:49
  • 3
    @initial_D: textbooks usually number their theorems. If you are using a precise formulation it may be worth stating "Theorem X.Y.Z from Chapter A of Book B"; if you are relying on something more general just "[BookReference, Chapter nnn]" will do. Jul 5, 2016 at 3:24
  • 2
    @Ooker On the contrary, it's very important to be explicit: otherwise, I've had reviewers from the other discipline get very confused about what's first-year studies vs. what's novel and controversial.
    – jakebeal
    Jul 5, 2016 at 3:50
  • 2
    @Ooker You misunderstand me, if I understand you correctly: when referencing standard material from another field, be explicit and cite a textbook. Citing a textbook says: "this is standard well-accepted stuff, even if it's unfamiliar to you."
    – jakebeal
    Jul 5, 2016 at 4:37
  • 1
    @Ooker You mean like "as found in this textbook by Smith & Lu [cite]"? No, I don't think you need to identify the textbook in prose; the citation is fine for that, and if it's standard material, the particular identity of the textbook is likely not that important.
    – jakebeal
    Jul 5, 2016 at 12:26

I'm not sure how things are done in math, but if these theorems are "quite standard" and common knowledge, I would think you could mention them, and say something along the lines of "for a reference" or "for further discussion" see XYZ textbook

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .