Ishkin, Khabir, and A. A. Nabiullina. “Asymptotics of Solutions of the Sturm–Liouville Equation With Meromorphic Potential”. Journal of Mathematics, Mechanics and Computer Science 104, no. 4 (December 19, 2019): 24–31. Accessed July 22, 2024. https://bm.kaznu.kz/index.php/kaznu/article/view/671.