1. One machine scheduling with delayed precedence constraints;Balas,1992
2. Theory of Scheduling;Conway,1967
3. Computers and Intractability: A Guide to the Theory of NP-completeness;Garey,1979
4. Reducibility among combinatorial problems;Karp,1972
5. Fast approximation algorithms for knapsack problems;Lawler;Math. Oper. Res.,1979