Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
doi chieu » doc hieu, doi chi, ho chieu
hanh sinh » hanh tinh, hanh dinh, hinh sinh
manh toan » thanh toan, anh tuan, tinh toan
san toan » van toan, dan toan, xuan toan
sinh va » sinh vat, tinh va, dinh van

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sach - hanh sinh va nhung cong ((san toan) OR (((manh toan) OR (thanh san)))) tap~".
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - hanh sinh va nhung cong ((san toan) OR (((manh toan) OR (thanh san)))) tap*.