Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
trung cac » truong cac, trung cap, trong cac
cac thanh » bac thanh, cach nhanh, ban thanh
hieu luc » hieu luat, hieu qua
cong san » cong tac
san tuan » van tuan, san luan, san quan
tuan cao » toan cao, juan cao, quang cao

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 luc) or (chieu sach)) - thanh trung cac thanh cong san tuan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu luc) OR (chieu sach)) - thanh trung cac thanh cong san tuan cao.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu luc) or (chieu sach)) - thanh trung cac thanh cong san tuan cao*.