Perhaps you should try some spelling variations:
viet tech » viet sach
nang dong » nang song, lang dong, nang luong
doi viet » dai viet, hoi viet, oi viet
tung cao » truong cao, trung cap, quang cao
nung cao » nang cao, nhung cau, quang cao
dong dan » dong danh, duong dan, dong san
toan ban » van ban
toan cao » toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doi viet tech - thanh ((tung cao) OR (nung cao)) nang dong dan ((toan ban) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi viet tech - thanh ((tung cao) OR (nung cao)) nang dong dan ((toan ban) OR (toan cao))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi viet tech - thanh ((tung cao) OR (nung cao)) nang dong dan ((toan ban) or (toan cao))*".