TITLE: Texts on moduli of elliptic curves
QUESTION [5 upvotes]: I want to study FLT (Fermat's Last Theorem), and now I'm studying moduli of elliptic curves.
I've heard that Deligne-Rapoport, Katz-Mazur, Mazur's "Modular curves...", and Katz's "p-adic..." are very good for this topic.
But I don't know what's the difference between these papers.
For me it seems that these treat almost same topics.
So what should I read at first?
(Now I'm reading Katz-Mazur.
It's easy to read even for me, a beginner of arithmetic geometry.
So I think I should read it at first.
And glancing through Mazur, it seems to use many results from other 3 papers.)
And would you recommend other good papers which I read understand for understanding FLT?
Any help will be much appreciated!

REPLY [2 votes]: Not having been mentioned before, I would recommend the two books "Fermat's Last Theorem, Basic Tools" and "Fermat's Last Theorem, The Proof" by Takeshi Saito. https://bookstore.ams.org/mmono-243 and https://bookstore.ams.org/mmono-245.
In particular, moduli of elliptic curves appear in chapter 2.2 but only over $\mathbb{Q}$. Then the second volume starts with chapter 8 "Modular curves over $\mathbb{Z}$" which covers the topics on the moduli spaces of elliptic curves needed for Fermat's Last Theorem.