ORDERS, S.S. Georgievska, A BOUNDARY PROBLEM OF THE THIRD AND FOURTH. AS A PRODUCT OF BOUNDARY PROBLEMS OF THE SECOND ORDER. Matematichki Bilten, [S. l.], v. 18, n. 1, 1994. Disponível em: https://bilten.smm.org.mk/index.php/bilten/article/view/1532. Acesso em: 13 jun. 2026.