RomanenkoI. B., and SkrypnikI. V. “A Priori Estimates of Solutions of Linear Parabolic Problems With Coefficients from Sobolev Spaces”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 11 (November 25, 1999): 1534–1548. Accessed November 22, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4755.