[1]
V. M. Borok and E. Kengne, “Classification of nonlocal boundary-value problems on a narrow strip”, Ukr. Mat. Zhurn., vol. 46, no. 4, pp. 338–346, Apr. 1994, Accessed: Dec. 15, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5730