Khai Thac Khoang San Thong Nhat Joint Stock Company Address: Thon, Quang Village, Dong Tien Commune, Huu Lung District, Lang Son Province Enterprise code: 4900883732 Phone: 0917292208 Representative: Nguyen Ngoc Vui Dong Tien Commune, Huu Lung District, Lang Son ProvinceFounding date: 26 - 11 - 2021