HILLEFORS, Åke. Jorden forsvandt under os. Varv, [S. l.], v. 1978, n. 2, p. 35–49, 1978. DOI: 10.7146/varv.v1978i2.149513. Disponível em: https://tidsskrift.dk/varv/article/view/149513. Acesso em: 6 dec. 2025.