Matthew Beaumont John Thornton Abdul Sattar Michael J. Maher Solving Over-Constrained Temporal Reasoning Problems Using Local Search. 134-143 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3157&spage=134 2004 conf/pricai/2004 PRICAI db/conf/pricai/pricai2004.html#BeaumontTSM04