Digital Maps and Geospatial Data | Princeton University

Survey of India. "Refer to this map as: 1:20,000 Delhi guide map, first edition. Relief shown by 3 metres contour intervals (contours are approximate) and spot heights. "Published under the direction of Brigadier Gambhir Singh, Surveyor General of India, 1959." "With corrections of selected items up to July 1959." Verso: index to places of interest.