Dimitris Vrakas Grigorios Tsoumakas Nick Bassiliades Ioannis P. Vlahavas HAPRC: an automatically configurable planning system. 41-60 2005 18 AI Commun. 1 http://iospress.metapress.com/openurl.asp?genre=article&issn=0921-7126&volume=18&issue=1&spage=41 db/journals/aicom/aicom18.html#VrakasTBV05