Yokus, Nihal, and Nimet Coskun. “Spectral Analysis of Klein-Gordon Difference Operator Given by a General Boundary Condition”. Communications in Mathematics and Applications 11, no. 2 (June 30, 2020): 271–279. Accessed May 3, 2024. https://www.rgnpublications.com/journals/index.php/cma/article/view/1328.