Instructor: Matthew Day
A reference for Stallings folding: Stallings foldings and the subgroup structure of free groups, by Kapovich and Myasnikov.
A reference for Stallings folding and automorphisms: Folding free-group automorphisms, by Richard D. Wade.
Notes on free groups. I wrote these for my other class, but they may help you review.
Updated the 12th of October, 2017.