PROTASOV, I. V.; SLOBODIANIUK, S. V. Thin Subsets of Groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 9, p. 1245–1253, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2505. Acesso em: 5 dec. 2025.