How we did it:
D.B. Shmoys, J.K. Lenstra, A.H.G. Rinnooy Kan, E.L. Lawler
Provides an in-depth treatment of the Traveling Salesman problem--the archetypical problem in combinatorial optimization. Each chapter deals with a different aspect of the problem, and has been written by an acknowledged expert in the field. Focusses on the essential ideas in a self-contained manner. Includes exercises and an extensive bibliography.