Duong, Nguyen Thuy, 		Huong, Nguyen Thi Nhu, 		Huong, Nguyen Van, AND 		Phuong, Ta Hoa.
" Assessment of Geoheritage of Geosites in Dong Van District, Ha Giang Province" <em>VNU Journal of Science: Earth and Environmental Sciences</em> [Online], Volume 35 Number 1 (26 March 2019)