WILLIAMS, E. F. University of Colorado at Boulder Map Library. Cartographic Perspectives, [S. l.], n. 39, p. 47–50, 2001. DOI: 10.14714/CP39.640. Disponível em: https://cartographicperspectives.org/index.php/journal/article/view/cp39-williams. Acesso em: 28 mar. 2024.