I have the following doubt. I'm writing a paper and I cite a lot of results that appear in Schikhof's "Ultrametric Calculus". Some of this results are put as exercises in Schikhof's book. This exercises are not difficult but are laborious, thus, if I write the proofs, the article may extend in about two or three pages.

Should I write the proofs or just simply cite them? Schikhof is a very well respected mathematician, and I have never found any errata 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 they are about five exercises.)

Thank you in advance.