RT Journal Article SR 00 A1 Filippova, T.F. A1 Kurzhanski, A.B. A1 Sugimoto, K. A1 Valyi, I. T1 Ellipsoidal calculus, singular perturbations and the state estimation problems for uncertain systems JF Journal of Mathematical Systems, Estimation, and Control YR 1996 FD 1996 VO 6 IS 3 SP 323 OP 338 PB Birkhauser Verlag SN 1052-0600 LK https://pure.iiasa.ac.at/id/eprint/4689/