SAMOILENKO, Yu. S.; POPOVYCH, S. V.; KRUGLYAK, S. A. The spectral problem and algebras associated with extended Dynkin graphs. I. Methods of Functional Analysis and Topology, [S. l.], v. 11, n. 4, p. 383–396, 2005. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/296. Acesso em: 16 dec. 2025.