Perhaps you should try some spelling variations:
hieu nganh » vien nganh, hiem ngan, hieu manh
canh trinh » canh tranh, hanh trinh, canh tinh
trinh xay » trinh ky
hoc hieu » hoc thieu, hoc hien, doc hieu
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
hang dau » hang va, hang tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu nganh - canh trinh xay dung ((cong tan) or (cong tac)) hang dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu nganh - canh trinh xay dung ((cong tan) OR (cong tac)) hang dau*.