Olǧar, H., F. Muhtarov, and O. Mukhtarov. “Operator-Pencil Treatment of Multi-Interval Sturm-Liouville Equation With Boundary-Transmission Conditions”. Bulletin of the Karaganda University. Mathematics Series 115, no. 3 (September 30, 2024): 126–136. Accessed July 10, 2025. http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/820.