KolodyI. M. “Estimate of the Maximum of Modulus of Generalized Solutions of the First Boundary-Value Problem for Degenerate Parabolic Equations”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 49, no. 12, Dec. 1997, pp. 1624–1637, https://umj.imath.kiev.ua/index.php/umj/article/view/5167.