Lyapunov first method for nonholonomic systems with circulatory forces. - Miroslav Veskovic; Vukman Covic (Math. Comput. Model., 2007)

On the instability of equilibrium of nonholonomic systems with nonhomogeneous constraints. - Vukman Covic; Miroslav Veskovic; Aleksandar Obradovic (Math. Comput. Model., 2010)