Khachatryan Kh. A., and Petrosyan H. S. “On Bounded Solutions of a Class of Nonlinear Integral Equations on the Plane and the Urysohn Equation in a Quadrant of the Plane”. Ukrains’kyi Matematychnyi Zhurnal 73, no. 5 (May 24, 2021): 695 - 711. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6541.