Paolo Giorgini John Mylopoulos Eleonora Nicchiarelli Roberto Sebastiani Formal Reasoning Techniques for Goal Models. 1-20 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2800&spage=1 2003 journals/jods/2003 J. Data Semantics 1 db/journals/jods/jods1.html#GiorginiMNS03