Survey of India. "Refer to this map as: One inch Delhi and locality, third edition. Gridded. " Relief shown by 50 ft contour interval (contours are approximated) and spot heights. Inset: map eastward continuation. "Published under the direction of Brigadier G. F. Heaney, Surveyor General of India. In upper left margin: Surveyed: 1910-11, 1914-15, 1920-21, 1925-28, 1930, 1931-34, 1935-36, 1947-50. In lower left margin: 1st ed 1930 (with title Delhi Province; 2nd ed 1946 with title Delhi and surrounding country; 3rd ed. 1950.