A.M.S. (Series) ; L751. "Fourth Edition-AMS (FEC)". Transverse Mercator projection. "Prepared under the direction of the Chief of Engineers by the Army Map Service (AMNS), Corps of Engineers, Department of the Army, Washington, D.C. Compiled in 1947 from Korea 1:50,000, Japanese Imperial Land Survey, Ch’ŏngjin, 1937; USHO Charts No.3248 (inset), 1942; 3248, 1942.... Aerial photography 1945.... Planimetric detail revised from aerial photography dated 1950, by photo-planimetric methods, by the 64th Engineer Base Topographic Battalion. Universal Transverse Mercator Grid values revised, 1950." "Sino-Korean place name characters added in 1951 by 64th Engineer Base Topographic Battalion."