Čelikovský Sergej, Huang J. :  Continuous feedback asymptotic output regulation for a class of nonlinear systems having nonstabilizable linearization , Proceedings of the 37th IEEE Conference on Decision and Control, p. 3087-3092, IEEE Control Systems Society, (Tampa 1998) , IEEE Conference on Decision and Control /37./, (Tampa, US, 17.12.1998-19.12.1998) [1998]