I. I. Skrypnik, “Regularity of a Boundary Point for Degenerate Parabolic Equations with Measurable Coefficients”, Ukr. Mat. Zhurn., vol. 52, no. 11, pp. 1550–1565, Nov. 2000, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4560