JURAYEV SHAXZOD SHUXRATJONVICH. EIGENFUNCTION EXPANSIONS OF SECOND-ORDER ELLIPTIC OPERATORS. Ethiopian International Journal of Multidisciplinary Research, [S. l.], v. 13, n. 5, p. 1157–1160, 2026. Disponível em: https://eijmr.org/index.php/eijmr/article/view/6828. Acesso em: 19 may. 2026.