MYLYO, O. Ya.; STOROZH, O. G. A Differential Boundary Operator of the Sturm–Liouville Type on a Semiaxis with Two-Point Integral Boundary Conditions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 11, p. 1480–1485, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4186. Acesso em: 5 dec. 2025.