Evtukhov, V. M., & Shlepakov, O. R. (2012). Asymptotic representations of solutions of essentially nonlinear systems of ordinary differential equations with regularly and rapidly varying nonlinearities. *Ukrainsâ€™kyi Matematychnyi Zhurnal*, *64*(9), 1165-1185. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/2650