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
chan cao » chan cho, chat cao, chay cao
va hang » van hang, va nang, va lang

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

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