Claudia Cevenini Giuseppe Contissa Migle Laukyte Agent-Based Contracting In Virtual Enterprises. 225-232 2007 conf/ifip5-5/2007 Virtual Enterprises and Collaborative Networks http://dx.doi.org/10.1007/978-0-387-73798-0_23 db/conf/ifip5-5/ifip5-5-2007.html#CeveniniCL07