Nazarova, K.Zh., and K.I. Usmanov. “Unique Solvability of Boundary Value Problem for Functional Differential Equations With Involution”. Bulletin of the Karaganda University. Mathematics Series 103, no. 3 (September 30, 2021): 68–75. Accessed July 4, 2025. https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/459.