TITLE: Citing exercises in an article
QUESTION [45 upvotes]: I'm writing a paper in which I cite a lot of results that appear in Schikhof's Ultrametric Calculus. Some of these results are exercises in Schikhof's book. These exercises are not difficult, but are laborious. Thus, if I write the proofs, the article may extend by about two or three pages.
Should I write the proofs or simply cite them? Schikhof is a very well respected mathematician, and I have never found any errors in his book. Obviously, I have checked that the exercises are correct.
(If it were one exercise, I would write the proof in my article, as I have seen in other articles, but in my case there are about five exercises.)

REPLY [6 votes]: Here is one additional data point. The standard reference for symmetric function is Macdonald's "Symmetric functions and Hall polynomials". Most of the content of this book is in the exercises; each section of the book contains many pages of useful results and formulas stated without proof. According to Google Scholar, this book has been cited 7735 times, and it seems likely that many (most?) of these citations are references to exercises in the book.