• Minimal realizations of nonlinear systemsKotta, Ülle; Moog, Claude; Tõnso, MarisAutomatica2018 / p. 207-212 https://doi.org/10.1016/j.automatica.2018.05.007 https://www.scopus.com/sourceid/24909 https://www.scopus.com/record/display.uri?eid=2-s2.0-85047724688&origin=inward&txGid=fd9e996b7522a7ea841bfb48dd2aa142 https://jcr.clarivate.com/jcr-jp/journal-profile?journal=AUTOMATICA&year=2022 https://www.webofscience.com/wos/woscc/full-record/WOS:000441853900022
• 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 https://www.scopus.com/sourceid/21100456158 https://www.scopus.com/record/display.uri?eid=2-s2.0-84885804720&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3182%2F20130904-3-FR-2041.00080%29&sessionSearchId=b54b8b263198aa2b467a2e833e85bb3b
• Realization of discrete-time nonlinear input-output equations : polynomial approachKotta, Ülle; Tõnso, MarisAutomatica2012 / p. 255-262 https://www.sciencedirect.com/science/article/pii/S0005109811005413