HUMMEL, S. Zur Karte von Sikhim und Bhutân. ERDKUNDE, [S. l.], v. 6, n. 4, p. 287–289, 1952. DOI: 10.3112/erdkunde.1952.04.12. Disponível em: https://journals-test.ulb.uni-bonn.de/index.php/erdkunde/article/view/1049. Acesso em: 3 dec. 2024.