А.Sh. Shaldanbayev; А.А. Shaldanbayevа; B.А. Shaldanbay. ON SQUARE ROOT OF STURM-LIUVILLE OPERATOR. Известия НАН РК. Серия физико-математическая, [S. l.], n. 3, p. 97–113, 2019. Disponível em: http://89.250.84.46/physics-mathematics/article/view/1640. Acesso em: 10 янв. 2025.