ENNOLA, V. On a conjecture of H. J. Godwin on cubic units. Annales Fennici Mathematici, [S. l.], v. 12, n. 2, p. 319–328, 1987. DOI: 10.5186/aasfm.1987.1209. Disponível em: https://afm.journal.fi/article/view/134608. Acesso em: 25 nov. 2024.