MALAMUD, M. M.; MOGILEVSKII, V. I. Krein type formula for canonical resolvents of dual pairs of linear relations. Methods of Functional Analysis and Topology, [S. l.], v. 8, n. 4, p. 72–100, 2002. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/201. Acesso em: 18 dec. 2025.