BOZHOK, R.; ALBEVERIO, S.; DUDKIN, M. E.; KOSHMANENKO, V. D. Dense subspaces in scales of Hilbert spaces. Methods of Functional Analysis and Topology, [S. l.], v. 11, n. 2, p. 156–169, 2005. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/274. Acesso em: 16 dec. 2025.