USERY, E. L. Geographical Information Systems: Principles and Applications. Cartographic Perspectives, [S. l.], n. 13, p. 21–22, 1992. DOI: 10.14714/CP13.1002. Disponível em: https://cartographicperspectives.org/index.php/journal/article/view/cp13-usery. Acesso em: 23 apr. 2024.