“Nonlinear Normal Modes of Forced Oscillations of Piecewise Linear Systems”. Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics, no. 1018 (October 15, 2012): 76–83. Accessed October 24, 2026. https://periodicals.karazin.ua/mech_math/article/view/13172.