Shevchuk, R.V., I.Ya. Savka, and Z.M. Nytrebych. “The Nonlocal Boundary Value Problem for One-Dimensional Backward Kolmogorov Equation and Associated Semigroup”. Carpathian Mathematical Publications 11, no. 2 (December 31, 2019): 463–474. Accessed June 17, 2024. https://journals.pnu.edu.ua/index.php/cmp/article/view/2124.