Moawia Elfaki Yahia Ramlan Mahmod Neural Expert System with Two Engines of Rough Set. 52-58 2001 conf/aiccsa/2001 AICCSA http://csdl.computer.org/comp/proceedings/aiccsa/2001/1165/00/11650052abs.htm db/conf/aiccsa/aiccsa2001.html#YahiaM01