Integer Programming and Combinatorial Optimization 7th International IPCO Conference, Graz, Austria, June 9-11, 1999, Proceedings - Cornuejols, Gerard; Cornuejols, Gerard; Burkard, Rainer E.; Burkard, Rainer E.; Woeginger, Gerhard J.; Woeginger, Gerhard J. (Springer Berlin Heidelberg : Imprint: Springer, 1999)