Sleptsova, I. P., and A. E. Shishkov. “Phragmen-Lindelof Principle for Some Quasilinear Evolution Equations of the Second Order”. Ukrains’kyi Matematychnyi Zhurnal 57, no. 2 (February 25, 2005): 239–249. Accessed May 4, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3591.