Eshkabilov, Yu. Kh. “Necessary and Sufficient Condition for Solvability of a Partial Integral Equation”. Methods of Functional Analysis and Topology 15, no. 1 (March 25, 2009): 67–73. Accessed December 16, 2025. https://zen.imath.kiev.ua/index.php/mfat/article/view/410.