Perhaps you should try some spelling variations:
nhieu tang » chieu sang, nhiet nang
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, hieu van
dung cong » dung trong
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
va dung » van dung, va duong, vat dung

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