Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu lang » chieu sang, hieu quang, nhieu tang
hoc dang » hoc dung, hoc bang, hoc tang
cong tac » cong ty
tac than » tac thanh, tam than, tac nhan
than cau » toan cau, phan cau, than cap
ho hieu » ho chieu, hoi hieu, nho hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - thanh trung ((hoc dang) or (hoc dan)) cong tac than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - thanh trung ((hoc dang) OR (hoc dan)) cong tac than cau.
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - thanh trung ((hoc dang) or (hoc dan)) cong tac than cau*.