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 va » truong va, trang va, trung ha
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cao » toan ban, toan tap

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