1. Introduction to Algorithms;Cormen,2009
2. Reducibility among combinatorial problems;Karp,1972
3. Combinatorial auctions;Abrache;Ann. OR,2007
4. A set-covering based heuristic algorithm for the periodic vehicle routing problem;Cacchiani;Discrete Appl. Math.,2014
5. An integer programming approach to the vehicle scheduling problem;Foster;J. Oper. Res. Soc.,1976