@MISC{MINLP129,
author = {Vecchietti, Aldo, Grossmann, Ignacio},
title = {Medium-Term Purchasing Contracts},
note = {Available from CyberInfrastructure for MINLP [{\tt www.minlp.org}, a collaboration of Carnegie Mellon University and IBM Research] at: {\tt www.minlp.org/library/problem/index.php?i=129}},
month = {Modification of: 13:26:54, June 25},
year = {2011},
}