Dung, Bui Quang, and Uong Dinh Khanh. “CALCULATION OF VIETNAM’S COASTLINE LENGTH (MAINLAND) BASED ON TOPOGRAPHIC MAP SYSTEM AT SCALE 1 50,000”. Vietnam Journal of Marine Science and Technology, vol. 16, no. 3, Aug. 2016, pp. 221-7, doi:10.15625/1859-3097/16/3/8654.