Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
hieu quan » hieu qua, lieu quan, thien quan
trung cua » truong cua, trung tuan, trung cap
cua tong » cua cong, cua dong, cua nong
cong tac » cong ty
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu quan)) - thanh trung cua tong ((cong san) OR (cong tac)) toan ban~.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu quan)) - thanh trung cua tong ((cong san) or (cong tac)) toan ban*.