Kovtun, I. I., and M. N. Feller. 2010. “Boundary-Value Problems for a Nonlinear Parabolic Equation With Lévy Laplacian Resolved With Respect to the Derivative”. Ukrains’kyi Matematychnyi Zhurnal 62 (10), 1400–1407. https://umj.imath.kiev.ua/index.php/umj/article/view/2964.