2 citations to https://www.mathnet.ru/rus/mzm1188

1. Iksanov A., Pilipenko A., “a Functional Limit Theorem For Locally Perturbed Random Walks”, Prob. Math. Stat.., 36:2 (2016), 353–368        
2. Pilipenko A.Yu., Prikhod'ko Yu.E., “on the Limit Behavior of a Sequence of Markov Processes Perturbed in a Neighborhood of the Singular Point”, Ukr. Math. J., 67:4 (2015), 564–583