Dau Tu Phat Trien Thang Long Lang Son Joint Stock Company Address: Khu Lien Hop Kinh Te Cua Khau Chi Ma, Chi Ma Hamlet, Yen Khoai Commune, Loc Binh District, Lang Son Province Enterprise code: 4900699317 Phone: 02053776155 Representative: Nguyen Phu Yen Yen Khoai Commune, Loc Binh District, Lang Son ProvinceFounding date: 12 - 1 - 2012