Vladimir Sidorov Vitaly Telerman Industrial Application of External Black-Box Functions in Constraint Programming Solver. 415-422 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2890&spage=415 2003 conf/ershov/2003 Ershov Memorial Conference db/conf/ershov/ershov2003.html#SidorovT03