KVEDARAS, B. On the boundary value problem with integral conditions for the systems of differential equations of second order. Lithuanian Mathematical Journal, [S. l.], v. 7, n. 1, p. 59–77, 1967. DOI: 10.15388/LMJ.1967.19935. Disponível em: https://www.journals.vu.lt/LMJ/article/view/19935.. Acesso em: 4 may. 2024.