Perhaps you should try some spelling variations:
quan trong » gian trong
cong thanh » cong trinh, truong thanh
dong thanh » truong thanh
hieu lang » chieu sang, hieu quang, nhieu tang
thanh hoa » thanh pho
doc hieu » toc thieu, hoc thieu, hoc hien
hoa quan » hoa luan, hoa qua, hoa dan
cong tan » cong tac, cong san, cong ty
than cap » khan cap, thanh lap, thanh cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu lang - thanh hoa quan trong ((cong tan) or (((cong thanh) OR (dong thanh)))) than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - thanh hoa quan trong ((cong tan) OR (((cong thanh) OR (dong thanh)))) than cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu lang - thanh hoa quan trong ((cong tan) or (((cong thanh) OR (dong thanh)))) than cap".
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - thanh hoa quan trong ((cong tan) or (((cong thanh) OR (dong thanh)))) than cap*.