Dzhamalov, S. Z. 2019. “Correctness of One Nonlocal Boundary-Value Problem With Constant Coefficient for the Nonlinear Mixed-Type Equation of the Second Kind of the Second Order in the Space”. Ukrains’kyi Matematychnyi Zhurnal 71 (1): 47-58. https://umj.imath.kiev.ua/index.php/umj/article/view/1418.