Thakar, Sarita, and Pratiksha Demanna. “Periodic Indefinite Sturm-Liouville Problems With One Turning Point”. The Journal of the Indian Mathematical Society 89, no. 1-2 (January 27, 2022): 182–197. Accessed November 7, 2024. https://informaticsjournals.co.in/index.php/jims/article/view/26181.