?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.aulast=Hoover&rft.aufirst=Thomas+B.&rft.au=+Hoover+Thomas+B.&rft.volume=55&rft.issn=0001-6969&rft.pages=403-408&rft.title=Acta+scientiarum+mathematicarum&rft.atitle=Essentially+normal+composition+operators+on+L2&rft.date=1991&rft.issue=3-4&rft.genre=article