Alexander Brodsky Larry Kerschberg Samuel Varas Optimal Constraint Decomposition for Distributed Databases. 301-319 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3321&spage=301 2004 conf/asian/2004 ASIAN db/conf/asian/asian2004.html#BrodskyKV04