Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
dung cong » dung trong
hieu van » hieu va, thien van, lieu va
trung va » truong va, trang va, trung ha
tac than » tac thanh, tac nhan, bac thanh
tam than » ban than
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (hieu van)) - thanh trung va dung cong ((tac than) OR (tam than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu van)) - thanh trung va dung cong ((tac than) OR (tam than)) cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu van)) - thanh trung va dung cong ((tac than) OR (tam than)) cao*".