Makhnei O, Tatsii R. Expansion by eigenvectors in case of simple eigenvalues of singular differential operator. Carpathian Math. Publ. [Internet]. 2011 Jun. 30 [cited 2024 Nov. 24];3(1):94-105. Available from: https://vps.pnu.edu.ua/index.php/cmp/article/view/3959