I like that this textbook includes practice problems with full answer keys.
Product Tag: Combinatorics
Applied Combinatorics by Keller, Mitchel T., Trotter, William T.
This textbook is used in many universities across the country.
Combinatorics of Coxeter Groups, Björner & Brenti, VERY GOOD, Hardcover
This textbook has been a reliable resource for students for years.
