Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
tran tap » toan tap, tran tan, tran tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((hieu lang) or (chieu sach)) - thanh trung cua nhung ((cong tan) OR (cong tac)) tran tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((hieu lang) OR (chieu sach)) - thanh trung cua nhung ((cong tan) OR (cong tac)) tran tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((hieu lang) or (chieu sach)) - thanh trung cua nhung ((cong tan) OR (cong tac)) tran tap".
• Adding a wildcard symbol may retrieve word variants: doi ((hieu lang) or (chieu sach)) - thanh trung cua nhung ((cong tan) OR (cong tac)) tran tap*.