Realization of nonlinear systems described by input/output differential equations: Equivalence of different methods. - Ülle Kotta; Tanel Mullari (ECC, 2003)

Equivalence of Different Realization Methods for Higher Order Nonlinear Input Output Differential Equations. - Ülle Kotta; Tanel Mullari (Eur. J. Control, 2005)

Simplification of the generalized state equations. - Tanel Mullari; Ülle Kotta (Kybernetika, 2006)

State space realization of bilinear continuous-time input-output equations. - Ülle Kotta; Tanel Mullari; Alan Solon Ivor Zinober; Palle Kotta (Int. J. Control, 2007)

Transformation the Nonlinear System into the Observer Form: Simplification and Extension. - Tanel Mullari; Ülle Kotta (Eur. J. Control, 2009)

Discussion on: "Unified Approach to the Problem of Full Decoupling via Output Feedback". - Ülle Kotta; Tanel Mullari (Eur. J. Control, 2010)

Dual algebraic framework for discrete-time nonlinear control systems. - Zbigniew Bartosiewicz; Ülle Kotta; Claude H. Moog; Tanel Mullari; Ewa Pawluszewicz (CDC, 2012)

Extended observer form: simple existence conditions. - Vadim Kaparin; Ülle Kotta; Tanel Mullari (Int. J. Control, 2013)

On accessibility conditions for state space nonlinear control systems on homogeneous time scales. - Zbigniew Bartosiewicz; Ülle Kotta; Tanel Mullari; Maris Tõnso; Malgorzata Wyrwas (Syst. Control. Lett., 2016)

Forward and Backward Shifts of Vector Fields: Towards the Dual Algebraic Framework. - Tanel Mullari; Ülle Kotta; Zbigniew Bartosiewicz; Ewa Pawluszewicz; Claude H. Moog (IEEE Trans. Autom. Control., 2017)

Weak reachability and controllability of discrete-time nonlinear systems: generic approach and singular points. - Tanel Mullari; Ülle Kotta; Zbigniew Bartosiewicz; Mohammad Amin Sarafrazi; Claude H. Moog; Ewa Pawluszewicz (Int. J. Control, 2020)

Extended observer form with vector fields. - Tanel Mullari; Ülle Kotta; Arvo Kaldmäe; Vadim Kaparin; Ashutosh Simha (Int. J. Control, 2024)

Extended Observer Forms for Submersive Discrete-Time Systems. - Ashutosh Simha; Vadim Kaparin; Tanel Mullari; Ülle Kotta (IEEE Trans. Autom. Control., 2024)