Gomilko AM, Pivovarchik VN. Inverse Sturm-Liouville problem on a figure-eight graph. Ukr. Mat. Zhurn. [Internet]. 2008Sep.25 [cited 2024Apr.20];60(9):1168–1188. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3235