Tallichetty S. Chandrashekar Y. Narahari The Core and Shapley Value Analysis for Cooperative Formation of Procurement Networks. 175-184 2007 conf/wecwis/2007 CEC/EEE http://doi.ieeecomputersociety.org/10.1109/CEC-EEE.2007.95 db/conf/wecwis/cec2007.html#ChandrashekarN07