Karen Aardal, Arjen K. Lenstra. Hard Equality Constrained Integer Knapsacks. In William Cook, Andreas S. Schulz, editors, Integer Programming and Combinatorial Optimization, 9th International IPCO Conference, Cambridge, MA, USA, May 27-29, 2002, Proceedings. Volume 2337 of Lecture Notes in Computer Science, pages 350-366, Springer, 2002. [doi]