PAKDAMAN, Ali; TORABI, Hamid; MASHAYEKHY, Behrooz. ON THE EXISTENCE OF CATEGORICAL UNIVERSAL COVERINGS. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 37, p. 289–300, 2017. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6709. Acesso em: 16 sep. 2026.