Оvsepyan K. H. Type of some nuclear subalgebras of the Toeplitz algebra generated by the inverse subsemigroups of a bicyclic semigroup. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 69, n. 11, p. 1551–1563, 2017. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1802. Acesso em: 5 dec. 2025.