The minimal time-varying realization of a nonlinear time-invariant system?Kotta, Ülle; Moog, Claude H.; Tõnso, Maris9th IFAC Symposium on Nonlinear Control Systems 2013 : Toulouse, France, 4 - 6 September 20132013 / p. 518 - 523 https://doi.org/10.3182/20130904-3-FR-2041.00080 Conference Proceedings at Scopus Article at Scopus Towards integrability for nonlinear time-delay systemsKaldmäe, Arvo; Moog, Claude H.; Califano, ClaudiaIFAC-Papers OnLine2015 / p. 900-905 https://doi.org/10.1016/j.ifacol.2015.09.305 Conference proceedings at Scopus Article at Scopus