2019-12-162019-12-16http://hdl.handle.net/1885/1955767 MB1 map169 MB1 map300 dpiimage/jpgimage/tiffenCopyright ExpiredTopographicVietnam -- MapsVietnam , Ap Gai-Bac, Series: L7014, Sheet 6631 lV, 1967, 1:50 00019672019-12-16