Bandyrskii, B., I. Lazurchak, V. Makarov, and M. Sapagovas. “Eigenvalue Problem for the Second Order Differential Equation With Nonlocal”.
Nonlinear Analysis: Modelling and Control 11, no. 1 (February 27, 2006): 13–32. Accessed April 11, 2025.
https://www.journals.vu.lt/nonlinear-analysis/article/view/14762.