Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
cua trung » cua truong, xuan trung, cua nhung
cong cua » cong cu, dong cua, huong cua
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.

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