?url_ver=Z39.88-2004&rft_id=10.1007%2FBF00264365&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=De+Nicola%2C+Rocco&rft.aulast=De+Nicola&rft.aufirst=Rocco&rft.issn=0001-5903&rft.volume=24&rft.issue=2&rft.pages=211-237&rft.atitle=Extensional+Equivalences+for+Transition+Systems&rft.title=Acta+Informatica&rft.date=1987&rft.genre=article