Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
trung cua » truong cua, trung tuan, trung cap
cua dong » chua dong, cua cong, cua dang
cong dan » cong san, cong tan, huong dan
cong tac » cong ty
toan ban » van ban

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: ho ((chieu sang) OR (hieu lang)) - thanh trung cua dong ((cong dan) OR (cong tac)) toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) OR (hieu lang)) - thanh trung cua dong ((cong dan) or (cong tac)) toan ban~".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) OR (hieu lang)) - thanh trung cua dong ((cong dan) or (cong tac)) toan ban*.