LEHMANN, H. Gesellschaften und Institute. ERDKUNDE, [S. l.], v. 3, n. 1, p. 54–56, 1949. DOI: 10.3112/erdkunde.1949.01.08. Disponível em: https://journals-test.ulb.uni-bonn.de/index.php/erdkunde/article/view/917. Acesso em: 11 dec. 2024.