LEBID’, V. O.; NIZHNIK, L. P. Spectral Analysis of Some Graphs with Infinite Rays. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 66, n. 9, p. 1193–1204, 2014. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2210. Acesso em: 5 dec. 2025.