?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Filippova%2C+T.F.&rft.aulast=Filippova&rft.aufirst=T.F.&rft.issue=3&rft.volume=6&rft.date=1996&rft.issn=1052-0600&rft.atitle=Ellipsoidal+calculus%2C+singular+perturbations+and+the+state+estimation+problems+for+uncertain+systems&rft.title=Journal+of+Mathematical+Systems%2C+Estimation%2C+and+Control&rft.pages=323-338&rft.genre=article