REDCHUK, I. K. Separating functions, spectral theory of graphs, and locally scalar representations in Hilbert spaces. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 1, p. 36–46, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3433. Acesso em: 5 dec. 2025.