Bit of a brain dump here. Serre's Trees was pretty relevant to my studies, though left quite a few gaps for the reader to fill in. Meier's Groups, Graphs and T

Bit of a brain dump here. Serre's Trees was pretty relevant to my studies, though left quite a few gaps for the reader to fill in. Meier's Groups, Graphs and Trees is much more accessible and visual. Strongly recommended! Knuth's notes on how to write mathematics well [1] were very influential. Munkres' Topology is a classic, but I think I leaned more on Hatcher's Algebraic Topology towards the end. Drobot's Formal Languages and Automata Theory was a lot of fun to self-study. The Graduate Texts in Mathematics series was always reliable in my experience. [1]: https://www-cs-faculty.stanford.edu/~knuth/klr.html https://www-cs-faculty.stanford.edu/~knuth/klr.html