GUY, R. E. The Availability of International Topographic Maps. Cartographic Perspectives, [S. l.], n. 09, p. 23, 1991. DOI: 10.14714/CP09.1073. Disponível em: https://cartographicperspectives.org/index.php/journal/article/view/cp09-guy. Acesso em: 15 may. 2024.