NYDAHL, L. Grand Canyon. Varv, [S. l.], v. 1982, n. 2, p. 35–39, 1982. DOI: 10.7146/varv.v1982i2.146080. Disponível em: https://tidsskrift.dk/varv/article/view/146080. Acesso em: 7 jan. 2025.