Malyts’kaH. P. “The Third Mixed Problem for the Sonin Equation in a Half Space”. Ukrains’kyi Matematychnyi Zhurnal 45, no. 8 (August 25, 1993): 1109–1114. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5907.