Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thanh tung » thanh cong
hieu lang » chieu sang, nhieu tang, hieu van
trong dan » trong dang, trong san, trong tan
dan toan » van toan, dan than, manh toan
toan ban » van ban
tung va » trung va, tuong va, dung va
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: thien ((hieu lang) or (hieu quang)) - thanh tung va dung trong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thien ((hieu lang) OR (hieu quang)) - thanh tung va dung trong dan toan ban.
• Adding a wildcard symbol may retrieve word variants: thien ((hieu lang) or (hieu quang)) - thanh tung va dung trong dan toan ban*.