KmitI. Ya. “Fredholm Solvability of a Periodic Neumann Problem for a Linear Telegraph Equation”. Ukrains’kyi Matematychnyi Zhurnal 65, no. 3 (March 25, 2013): 381-391. Accessed November 23, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2425.