?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=+Vu+Nghia+D.&rft.aulast=Vu&rft.aufirst=Nghia+D.&rft.volume=16&rft.issn=0324-721X&rft.title=Acta+cybernetica&rft.pages=485-506&rft.atitle=Relationships+between+closure+operations+and+choice+functions+-+equivalent+descriptions+of+a+family+of+functional+dependencies&rft.date=2004&rft.issue=3&rft.genre=article