PERDUE, N. A. The Vertical Space Problem. Cartographic Perspectives, [S. l.], n. 74, p. 9–28, 2013. DOI: 10.14714/CP74.83. Disponível em: https://cartographicperspectives.org/index.php/journal/article/view/cp74-perdue. Acesso em: 28 mar. 2024.