LEHMANN, H. Tagungen und Kongresse. ERDKUNDE, [S. l.], v. 3, n. 1, p. 52–54, 1949. DOI: 10.3112/erdkunde.1949.01.07. Disponível em: https://journals-test.ulb.uni-bonn.de/index.php/erdkunde/article/view/916. Acesso em: 8 oct. 2024.