Le Suan Kan (1971) “On construction of approximate solutions for an autonomous difference second order equation describing oscillating processes with a considerable resistance force”, Ukrains’kyi Matematychnyi Zhurnal, 23(6), pp. 778-781. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/8626 (Accessed: 24November2024).