Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
hoc hieu » hoc thieu, hoc hien, doc hieu
tranh va » tranh van, trinh va, thanh va
trang va » tran van, hang va
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan cao » toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu nganh - canh ((tranh va) OR (trang va)) nhung ((cong tan) OR (cong san)) toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu nganh - canh ((tranh va) OR (trang va)) nhung ((cong tan) or (cong san)) toan cao~".
• Adding a wildcard symbol may retrieve word variants: hoc hieu nganh - canh ((tranh va) OR (trang va)) nhung ((cong tan) or (cong san)) toan cao*.