KIBENKO, A.; CHEPURNOWA, L. On one existence and uniqueness theorem. Lithuanian Mathematical Journal, [S. l.], v. 8, n. 3, p. 523–529, 1968. DOI: 10.15388/LMJ.1968.20587. Disponível em: https://www.zurnalai.vu.lt/LMJ/article/view/20587. Acesso em: 8 jun. 2025.