Team, S. “Derivative-Free Broyden’s Method for Inverse Partially Known Sturm-Liouville Potential Functions: Athassawat Kammanee”. Thai Journal of Mathematics, vol. 13, no. 1, Apr. 2015, pp. 237-44, https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/505.