?url_ver=Z39.88-2004&rft_id=10.1068%2Fa131085&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Leonardi%2C+G.&rft.aulast=Leonardi&rft.aufirst=G.&rft.issue=9&rft.volume=13&rft.date=September+1981&rft.issn=0308-518X&rft.atitle=A+unifying+framework+for+public+facility+location+problems+-+part+2%3A+some+new+models+and+extensions.&rft.title=Environment+and+Planning+A&rft.pages=1085-1108&rft.genre=article