Hisako Shiohara Yuichi Iizuka T. Maruyama Seiji Isobe Category Oriented Analysis for Visual Data Mining. 91-98 http://link.springer.de/link/service/series/0558/bibs/1614/16140091.htm 1999 conf/visual/1999 VISUAL db/conf/visual/visual99.html#ShioharaIMI99