1. Z. Bartosiewicz, ‘A new setting for polynomial continuous time systems, and a realization theorem’, to appear in J. Mathematical Control and Information, 1985
2. C.R. Acad. Sc. Paris 296, serie;D Claude,1983
3. D. Claude, ‘Linéarisation par diffeomorphisme et immersion des systèmes’, Rapport de Laboratoire des Signaux et Systèmes, C.N.R.S.-E.S.E., France
4. M. Fliess and I. Kupka, ‘A finiteness criterion for nonlinear input-output differential systems’, SIAM J. Control Opt. 21, 1983, p.721–728
5. R. Hermann and A. Krener, ‘Nonlinear controllability and observability’, IEEE Transactions on Automatic Control, AC-22, 1977, p.728–740