Nicholas Mark Gotts J. Gareth Polhill Alistair N. R. Law Aspiration Levels in a Land Use Simulation. 663-683 2003 34 Cybernetics and Systems 8 http://taylorandfrancis.metapress.com/openurl.asp?genre=article&issn=0196-9722&volume=34&issue=8&spage=663 db/journals/cas/cas34.html#GottsPL03