SEIFERT, B. G. Classification of fibred group extensions and $H^1$. MATHEMATICA SCANDINAVICA, [S. l.], v. 58, p. 105–113, 1986. DOI: 10.7146/math.scand.a-12132. Disponível em: https://www.mscand.dk/article/view/12132. Acesso em: 24 nov. 2024.