Kurta V. V. “On the Fragmen–Lindelof Theorems for Quasilinear Elliptic Equations of the Second Order ”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 44, no. 10, Oct. 1992, pp. 1376-81, https://umj.imath.kiev.ua/index.php/umj/article/view/8234.