Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
trung hoc » trung quoc
dung hoc » dong hoc, dung thuoc, dung khoa
cong ban » cong bang, cong san, cong dan
cong tan » cong tac, cong san, cong thanh
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chieu sach - thanh ((trung hoc) or (dung hoc)) thuong ((cong ban) OR (cong tan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - thanh ((trung hoc) OR (dung hoc)) thuong ((cong ban) OR (cong tan)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sach - thanh ((trung hoc) or (dung hoc)) thuong ((cong ban) OR (cong tan)) toan cao".
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - thanh ((trung hoc) or (dung hoc)) thuong ((cong ban) OR (cong tan)) toan cao*.