A.M.S. (Series) ; L751. "Sixth edition-AMS (FEC)". Transverse Mercator projection. "Prepared by the Army Map Service (AMNS), Corps of Engineers, U.S. Army, Washington, D.C. Compiled in 1951 from Korea, 1:50,000, Japanese Imperial Land Survey, Yanghap-tong, 1941. Planimetric detail revised by photo-planimetric methods. Aerial photography Sept., Oct. 1950.... Road classifications revised in July, Sept. 1951, by the 64th Engineer Base Topographic Battalion, from reconnaissance material furnished by the Engineer, EUSAK, 1951."