Wang, Y. P., Yiteng Hu, and Chung-Tsun Shieh. “The Partial Inverse Nodal Problem for Differential Pencils on a Finite Interval”. Tamkang Journal of Mathematics 50, no. 3 (September 2, 2019): 307–319. Accessed April 29, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/3359.