While in the 4.0 era, Viettel's social responsibility is standing aspect by side with multiple units and corporations to make options to develop a breakthrough technological know-how, participating for a prosperous Vietnam.2011: Nhà cung c?p d?ch v? vi?n thông t?t nh?t th? gi?i t?i các th? tr??ng ?ang phát tri?n – WCA.H? tr? khách hàng Câu