Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu sach » chieu sach, hieu cach, dien sach
trung cua » truong cua, trung tuan, trung cap
cua thong » cua thuong, cua khong, cua tong
doc hieu » toc thieu, hoc thieu, hoc hien
cong tac » cong ty
gian cau » gian chau, gian cac, gian cam

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