Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
hoi hieu » hoi phieu, hoi tieu, moi hieu
cong cac » cuong cac, cong cau, trong cac
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
toan cao » toan ban, toan tap
cac han » cac nhan, cac phan, cac dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - thanh cong cac han ((cong tan) or (cong tac)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - thanh cong cac han ((cong tan) OR (cong tac)) toan cao.
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - thanh cong cac han ((cong tan) or (cong tac)) toan cao*.