Yoshiaki Okubo Makoto Haraguchi Yan Fang Zheng A Method for Finding Consistent Hypotheses Using Abstraction. 313-316 2000 conf/sara/2000 SARA http://link.springer.de/link/service/series/0558/bibs/1864/18640313.htm db/conf/sara/sara2000.html#OkuboHZ00