R. K. Amirov, B. Keskin, and G. Özkan, “Direct and inverse problems for the Dirac operator with a spectral parameter linearly contained in a boundary condition”, Ukr. Mat. Zhurn., vol. 61, no. 9, pp. 1155–1166, Sep. 2009, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3088