Ilja Ponka Nicholas R. Jennings Changing Circumstances and Leveled Commitment: A Compensatory Approach to Contracting. 185-191 2007 conf/wecwis/2007 CEC/EEE http://doi.ieeecomputersociety.org/10.1109/CEC-EEE.2007.31 db/conf/wecwis/cec2007.html#PonkaJ07