Zernov, A. E. “On the Solvability and Asymptotics of Solutions of One Functional Differential Equation With Singularity”. Ukrains’kyi Matematychnyi Zhurnal 53, no. 4 (April 25, 2001): 455–465. Accessed April 14, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/4268.