Михайленко, Василь Васильович, and Станіслав Васильович Михайленко. “RESEARCH METHOD OF STATIONARY VIBRATIONS FOR NONLINEAR SYSTEMS WITH MONOHARMONIC PERTURBATION”. PRECARPATHIAN BULLETIN OF THE SHEVCHENKO SCIENTIFIC SOCIETY. Number, no. 2(38), Feb. 2019, pp. 105-13, https://pvntsh.nung.edu.ua/index.php/number/article/view/40.