Package No. 4.2: Supply And Transportation Of Secondary Vttb And Configuration Of Kmt At Transformer Stations: Dong Anh 500Kv Substation, Pho Noi 500Kv Substation, Vat Cach 220Kv Substation, Ba Thien 220Kv Substation, Phu Tho 2 220Kv Substation