Sergaliyev, A. S., and L. A. Khajiyeva. “Modelling of Nonlinear Torsional-Flexural Vibrations of Drill Strings”. International Journal of Mathematics and Physics 6, no. 2 (December 26, 2015): 41–48. Accessed December 4, 2024. https://ijmph.kaznu.kz/index.php/kaznu/article/view/147.