Hoang Son Address: Tham Keo Hamlet, Coc Nam, Tan My Commune, Van Lang District, Lang Son Province Enterprise code: 4900237094 Phone: 02053850999 Representative: Trieu Thi Chan Adress: Khu Day Thep, Dong Dang Town, Cao Loc District, Lang Son Province Tan My Commune, Van Lang District, Lang Son ProvinceFounding date: 5 - 12 - 2005