1. Philosophiae Naturalis Principia Mathematica;Newton;Imprimatur S. Pepys, Reg. Soc. Prases., Londini,1686
2. Integrazione di inequazione differenziale presentatasi in electrotechnica;Tricomi;Ann. R. Scuola Norm. Sup. Pisa,1933
3. On an equation in the theory of electrical machines (in Russian);Belyustina,1955
4. Evaluation of the critical value for the generalized equation of a pendulum;Barbalat;Communic. Acad. R.P. Romania,1960
5. Dynamical Systems with Cylindrical Phase Space;Barbashin,1969