HELKIÆR JENSEN, R. L.S. Abramov (ed.): Theoretical Problems in Physical and Economic Geography, Vol. 1. Geografisk Tidsskrift, [S. l.], v. 75, 1976. Disponível em: https://tidsskrift.dk/geografisktidsskrift/article/view/45599. Acesso em: 9 maj. 2024.