Paul Waddell Alan Borning Hana Sevcikova David Socha Opus (the Open Platform for Urban Simulation) and UrbanSim 4. 360-361 2006 conf/dgo/2006 DG.O http://doi.acm.org/10.1145/1146598.1146702 db/conf/dgo/dgo2006.html#WaddellBSS06