?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=+Voiculescu+Dan&rft.aufirst=Dan&rft.aulast=Voiculescu&rft.pages=277-287&rft.date=1993&rft.atitle=A+note+on+the+augmentation+ideal+of+certain+rings+associated+with+free+groups&rft.title=Acta+scientiarum+mathematicarum&rft.volume=57&rft.issn=0001-6969&rft.issue=1-4&rft.genre=article