Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
trung dap » trung cap, trung dai, trung lap
trung dam » trung tam, trung dai, trong dam
cong dan » cong san, cong tan, cong dong
khan cap » khan ap, than cap, khoan cam

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 dap) OR (trung dam)) nhung ((cong dan) OR (huong dan)) khan cap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sach - thanh ((trung dap) or (trung dam)) nhung ((cong dan) OR (huong dan)) khan cap~".
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - thanh ((trung dap) or (trung dam)) nhung ((cong dan) OR (huong dan)) khan cap*.