Stephan Frank Petra Hofstedt Pierre R. Mai A Flexible Meta-solver Framework for Constraint Solver Collaboration. 520-534 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2821&spage=520 2003 conf/ki/2003 KI db/conf/ki/ki2003.html#FrankHM03