# Best way to cite well known theorems from a specific source

I am writing up a paper and I use some very well known theorems, such as the Chinese remainder theorem and quadratic reciprocity, and want to state them so that the document is as self contained as possible. Consequently, I need to provide a citation for these theorems and I am wondering what would be the best way to go about doing that. Currently I am considering two options- the first where I have a sentence preceding the statement of the theorem explaining where the theorem appears in the source I'm citing and the second option I am considering is simply stating the theorem accompanied by a parenthetical citation. So those options as they stand would likely read something like

The following theorem appears in (source 1) as proposition $n$.

Theorem $k$: If (condition) then (property)

or

Theorem $k$: If (condition) then (property) [parenthetical citation]

Does either of these options seem ideal or is there a better way I have not thought of to reference a source in a situation like this one?

• Provided the citation is specific, clear and easy to find, it doesn't really matter (i.e. include things like page numbers; there's nothing worse than citing a 500-page book for a result with no common name). If you want to publish it, journals tend to have stylistic specifications, but otherwise, look through a few expository articles and find a method you like. Personally, I tend to give the name/discoverer in brackets after theorem number, then use a square-bracketed full citation (i.e. "[1], Prop. 2, pp. 3ff.", or similar), or use a footnote if a longer description or comment is required. – Chappers Apr 23 '17 at 1:53
• You should cite Apostol number theory's book, it is easy to download. – reuns Apr 23 '17 at 3:47
• @Chappers that sounds good. I'll probably go along those lines. – Oiler Apr 23 '17 at 4:35
• @user1952009 I'm not looking for a source. I am looking for the best way to incorporate citations into my writing. – Oiler Apr 23 '17 at 4:36