?url_ver=Z39.88-2004&rft_id=10.1068%2Fa090653&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Willekens%2C+F.J.&rft.aulast=Willekens&rft.aufirst=F.J.&rft.issue=6&rft.volume=9&rft.date=March+1977&rft.issn=0308-518X&rft.atitle=Sensitivity+analysis+in+multiregional+demographic+models&rft.title=Environment+and+Planning+A&rft.pages=653-674&rft.genre=article