Marek Hatala Griff Richards Value-Added Metatagging: Ontology and Rule Based Methods for Smarter Metadata. 65-80 https://doi.org/10.1007/978-3-540-39715-1_5 2003 conf/semweb/2003ruleml RuleML db/conf/semweb/ruleml2003.html#HatalaR03