R. K. Amirov and V. A. Yurko, “On differential operators with singularity and conditions of discontinuity inside an interval”, Ukr. Mat. Zhurn., vol. 53, no. 11, pp. 1443–1457, Nov. 2001, Accessed: Apr. 09, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4364