Citing Math Proofs.

Question

I am writing a math paper on which $p$-gons are constructible by compass and straightedge and the construction of the $17$-gon. I am taking many proofs (but writing them in my own words) from a book, so that I can show another result. How exactly would I go about citing those proofs? If they are all from the same book, would I cite each one individually, or cite all of them at the end,after they have all been proven (they appear concurrently in the paper)? Additionally, if I am showing Felix Klein's solution to the construction of the $17$-gon, how would I cite that, seeing as the proof is rather long? Thanks!