Malyts’kaH. P. (1993) “The third mixed problem for the Sonin equation in a half space”, Ukrains’kyi Matematychnyi Zhurnal, 45(8), pp. 1109–1114. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5907 (Accessed: 24November2024).