Coşkun, Haskiz, and Ayşe Kabataş. “Asymptotic Approximations of Eigen-Functions for Regular Sturm-Liouville Problems With Eigenvalue Parameter in the Boundary Condition for Integrable Potential”. MATHEMATICA SCANDINAVICA 113, no. 1 (September 1, 2013): 143–160. Accessed August 13, 2026. https://tidsskrift.dk/math/article/view/15486.