Popov, G. Ya. “New Integral Transformations and Their Applications to Some Boundary-Value Problems of Mathematical Physics”. Ukrains’kyi Matematychnyi Zhurnal 54, no. 12 (December 25, 2002): 1642–1652. Accessed December 6, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/4203.