MalyshevК. I., and TikhonenkoN. Ya. “Direct Methods for the Approximate Solution of Operator Equations With Nonzero Kernel”. Ukrains’kyi Matematychnyi Zhurnal 50, no. 9 (September 25, 1998): 1202–1213. Accessed September 1, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4836.