Amir Ketata Sudhir P. Mudur Nematollaah Shiri Dependable performance analysis for fuzzy clustering of web usage data. 275-282 2009 CIDM http://dx.doi.org/10.1109/CIDM.2009.4938660 conf/cidm/2009 db/conf/cidm/cidm2009.html#KetataMS09