The Design of Approximation Algorithms
David P. Williamson & David B. Shmoys
Information Retrieval: Implementing and Evaluating Search Engines
Stefan Buttcher & Charles L. A. Clarke & Gordon V. Cormack
How to Prove It: A Structured Approach
Daniel J. Velleman
A First Course in Mathematical Modeling
Frank R. Giordano & Maurice D. Weir & William P. Fox
Algorithm Design
Jon Kleinberg & Éva Tardos