KOROBEINIK, J. F. On a lower bound of integral solutions of the differential equations of infinite order. Lithuanian Mathematical Journal, [S. l.], v. 5, n. 2, p. 251–259, 1965. DOI: 10.15388/LMJ.1965.19558. Disponível em: https://www.zurnalai.vu.lt/LMJ/article/view/19558. Acesso em: 5 jul. 2025.