Shevchuk, R.V., I.Ya. Savka, and Z.M. Nytrebych. 2019. “The Nonlocal Boundary Value Problem for One-Dimensional Backward Kolmogorov Equation and Associated Semigroup”. Carpathian Mathematical Publications 11 (2):463-74. https://doi.org/10.15330/cmp.11.2.463-474.