Qingqing Yuan Yubo Lou Haofeng Zhou Wei Wang 0009 Baile Shi Extract Frequent Pattern from Simple Graph Data. 158-169 2002 conf/waim/2002 WAIM http://link.springer.de/link/service/series/0558/bibs/2419/24190158.htm db/conf/waim/waim2002.html#YuanLZWS02