Montello, Daniel R., and M. Violet Gray. “Miscommunicating With Isoline Preference Maps: Design Principles for Thematic Maps”. Cartographic Perspectives, no. 50 (March 1, 2005): 24–33. Accessed June 22, 2026. https://cartographicperspectives.org/index.php/journal/article/view/cp50-montello-gray.