TITLE: Books or authors who write about how to write mathematics properly
QUESTION [6 upvotes]: I've always been interested how to write maths properly. Depending of the knowledge of the reader, you can't solve every detail of a proof of a theorem. You have to show the most important facts, unless your proof turns out tedious and languish. I'm writing a little paper about this to my students and I would like to know some authors who discuss about this, I need some references.

REPLY [2 votes]: Jean Pierre Serre is in some sense a reference on good article writing. I would  watch the awesome lecture of him "How to write mathematics badly". Gives very good insights that you could pass to your students.
I would also suggest Mathematical Writing, of Donald Knuth

REPLY [2 votes]: See these books:

A Primer of Mathematical Writing
by Steven G. Kranz.
Handbook of Writing for the Mathematical Sciences by Nicholas J. Hingham.