United States. Central Intelligence Agency. cartographic Maps. lcgft https://id.loc.gov/authorities/genreForms/gf2011026387 [Washington, D.C. : Central Intelligence Agency, 1957] eng "25863 3-57. SSO-655-5/57." Shows northern Quảng Trị Province, along Song Ben Hai River, which separates North and South Vietnam. Relief shown by spot heights. "Base: Indochina (series L605), 1:100,000 / U.S. Army Map Service ..." Vietnam--Administrative and political divisions--Maps. Vietnam Demilitarized Zone (Vietnam)--Maps. Vietnam. Available also through the Library of Congress Web site as a raster image. http://hdl.loc.gov/loc.gmd/g8021f.ct002841