Kolomiets Y. V. “Averaging for Partial Differential Equations Whose Coefficients Are Perturbed by Jump Markov Processes ”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 44, no. 10, Oct. 1992, pp. 1367-75, https://umj.imath.kiev.ua/index.php/umj/article/view/8233.