Felix Cheung Ben Kao David Wai-Lok Cheung Chi-Yuen Ng An Efficient Algorithm for Incremental Update of Concept Spaces. 368-380 2002 conf/pakdd/2002 PAKDD http://link.springer.de/link/service/series/0558/bibs/2336/23360368.htm db/conf/pakdd/pakdd2002.html#CheungKCN02