GromykA. P., Konet I. M., and Pylypiuk T. M. “Hyperbolic Boundary-Value Problem for a Piecewisehomogeneous Hollow Cylinder”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 12 (December 26, 2019): 1607-1617. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/714.