Gromyk, A. P., I. M. Konet, and T. M. Pylypiuk. “Hyperbolic Boundary-Value Problem for a Piecewisehomogeneous Hollow Cylinder”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 12 (December 26, 2019): 1607–1617. Accessed April 7, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/714.