W. C. Cho D. Richards Ontology construction and concept reuse with formal concept analysis for improved web document retrieval. 109-126 2007 5 Web Intelligence and Agent Systems 1 http://iospress.metapress.com/openurl.asp?genre=article&issn=1570-1263&volume=5&issue=1&spage=109 db/journals/wias/wias5.html#ChoR07