EvtukhovV. M., and ChernikovaA. G. 2017. “Asymptotic Behavior of the Solutions of Second-order differential Equations With Rapidly Varying Nonlinearities”. Ukrains’kyi Matematychnyi Zhurnal 69 (10), 1345-63. https://umj.imath.kiev.ua/index.php/umj/article/view/1786.