I. P. Sleptsova and A. E. Shishkov, “Phragmen-Lindelof Principle for Some Quasilinear Evolution Equations of the Second Order”, Ukr. Mat. Zhurn., vol. 57, no. 2, pp. 239–249, Feb. 2005, Accessed: Dec. 21, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3591