MASKIT, Bernard. A remark on degenerate groups. MATHEMATICA SCANDINAVICA, [S. l.], v. 36, p. 17–20, 1975. DOI: 10.7146/math.scand.a-11558. Disponível em: https://tidsskrift.dk/math/article/view/11558. Acesso em: 14 aug. 2026.