I. D. Pukalskyi, “Nonlocal Neumann problem for a degenerate parabolic equation”, Ukr. Mat. Zhurn., vol. 51, no. 9, pp. 1232–1243, Sep. 1999, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4719