Ronto, M. I., and T. V. Savina. “A Numerical-Analytic Method for Three-Point Boundary-Value Problems”. Ukrains’kyi Matematychnyi Zhurnal 46, no. 4 (April 25, 1994): 393–403. Accessed April 11, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5736.