Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
cong tac » cong ty
tac chan » tac chuan, tac can, tac chon
chan cau » phan cau, can cau, chinh cau

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: doi chieu sach - thanh ((trung cua) OR (trung cap)) trong cong tac chan cau~.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - thanh ((trung cua) or (trung cap)) trong cong tac chan cau*.