Bruce Spencer Sandy Liu Inference Queues for Communicating and Monitoring Declarative Information between Web Services. 121-135 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2876&spage=121 2003 conf/semweb/2003ruleml RuleML db/conf/semweb/ruleml2003.html#SpencerL03