IVANOV, S. V. On $*$-representations of algebras given by graphs. Methods of Functional Analysis and Topology, [S. l.], v. 13, n. 1, p. 17–27, 2007. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/333. Acesso em: 16 dec. 2025.