1. Subharmonic oscillations of a pendulum;Skalak;Journal of Applied Mechanics,1960
2. On the subharmonic oscillations of a pendulum;Struble;Journal of Applied Mechanics,1963
3. An analytical solution of the inverted pendulum;Phelps;American Journal of Physics,1965
4. The method of canonical averaging in the theory of nonlinear oscillations;Fedorchenko;Ukrainskii Matematicheskii Zhurnal,1957
5. Nonlinear oscillations of a gyroscopic pendulum with an oscillating point of suspension;Sethna,1964