I am writing up an essay, like a sort of project. It is not an academic paper, but it will be read and judged by some fellows.
I am trying to document or base my statements on a topic by including some proper references, and I am really in a bit of a hurry, so I do not have much time to search for 'the best' references.
Recently, I found one book (at Google Books) which seemed appropriate to me. I was somewhat suspicious because both the author and the publisher were unknown to me. I performed some additional searches at Google Books and at Google in general, and I found another book from the same publisher (and different author) which had overlapping paragraphs with the first book. And I also found some paragraphs of the first book in several websites, even Wikipedia.
I have not been able to determine whether there is an initial source or a mix of original sources.
So, this is the situation. My question: I would like to use the 'plagiarist' book as a reference. Is it appropriate to do so? Do you think I should add a sort of footnote stating that the reference is valid despite it seems to be plagiarising from other sources?
Regarding the authorship, it seems pretty convenient to me that, in the copyright page of these two books (which happen to be included among the preview-available pages at Google Books), you can find the copyright symbol before the publisher, but not before the name of the respective authors.
On the website of the publisher, you can read a short bio for each author, but you cannot figure out which university or company they work for. They seem made-up texts to me. So, maybe, the authors are totally fake!