Trung Tam Vien Thong 4 Address: Khu Tan Thinh, Tan Yen Town, Ham Yen District, Tuyen Quang Province Enterprise code: 5000584805 Phone: 02073843819 Tan Yen Town, Ham Yen District, Tuyen Quang ProvinceFounding date: 23 - 2 - 2010