Borisenko О. V. “Behavior of Non-Autonomous Oscillating System under the Influence of Small Random Perturbations in the Resonance Case ”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 44, no. 12, Dec. 1992, pp. 1645-51, https://umj.imath.kiev.ua/index.php/umj/article/view/8190.