Jan G. Bazan Andrzej Skowron Dominik Slezak Jakub Wroblewski Searching for the Complex Decision Reducts: The Case Study of the Survival Analysis. 160-168 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2871&spage=160 2003 conf/ismis/2003 ISMIS db/conf/ismis/ismis2003.html#BazanSSW03