NIZHNIK, L. P.; BRASCHE, J. F.; BEREZANSKY, Yu. M. On generalized selfadjoint operators on scales of Hilbert spaces. Methods of Functional Analysis and Topology, [S. l.], v. 17, n. 3, p. 193–198, 2011. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/483. Acesso em: 16 dec. 2025.