1. On the internal resonance of nonlinear systems with two degrees of freedom;Tondl;Nonlinear Vibration Problems,1963
2. Some Problems of Rotor Dynamics;Tondl,1965
3. Domains of attraction for nonlinear systems;Tondl;Monographs and Memoranda 8, Bechovice,1970
4. Resonance vibrations of nonlinear systems excited by a periodic non-harmonic force;Tondl;Monographs and Memoranda 13, Bechovice,1972
5. Vibrations of dynamical systems with quadratic non-linearities;Sethna;Journal of Applied Mechanics, Transactions of the American Society of Mechanical Engineers,1965