Duc Thanh Address: Tieu Khu Tran Dang Ninh, Bac Son Town, Bac Son District, Lang Son Province Enterprise code: 4900221376 Phone: 0205837529 Representative: Nong Thi Chinh Adress: Tieu Khu Tran Dang Ninh, Bac Son Town, Bac Son District, Lang Son Province Bac Son District, Lang Son ProvinceFounding date: 21 - 1 - 2003