AmanovR. A., and MamedovF. I. “On Some Properties of Solutions of Quasilinear Degenerate Equations”. Ukrains’kyi Matematychnyi Zhurnal 60, no. 7 (July 25, 2008): 918–936. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3209.