BOOTH, P. I. Fibrations and Cofibred Pairs. MATHEMATICA SCANDINAVICA, [S. l.], v. 35, p. 145–148, 1974. DOI: 10.7146/math.scand.a-11541. Disponível em: https://www.mscand.dk/article/view/11541. Acesso em: 2 may. 2024.