Daniel L. Moody Entity Connectivity vs. Hierarchical Levelling as a Basis for Data Model Clustering: An Experimental Analysis. 77-87 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2736&spage=77 2003 conf/dexa/2003 DEXA db/conf/dexa/dexa2003.html#Moody03