BazaliiB. V., & TedeevA. F. (1995). Method for symmetrization and estimation of solutions of the Neumann problem for the equation of a porous medium in domains with noncompact boundary for infinitely increasing time. Ukrains’kyi Matematychnyi Zhurnal, 47(2), 147–157. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/5398