E. S. Panakhov and M. Sat, “Inverse problem for interior spectral data of the hydrogen atom equation”, Ukr. Mat. Zhurn., vol. 64, no. 11, pp. 1516–1525, Nov. 2012, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2677