Perhaps you should try some spelling variations:
thanh dung » thanh duong, thanh tung, thanh hung
hieu lang » chieu sang, hieu quang, nhieu tang
tong cong » trong cong, cong cong, dung cong
dung cua » dung luan, dung cho
dan than » dan chan, van than, dan toan
ban than » ban thanh, van thanh, ban hang
ho hieu » ho chieu, hoi hieu, nho hieu

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 - thanh dung cua ((thong thong) OR (tong cong)) ((dan than) OR (ban than)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - thanh dung cua ((thong thong) or (tong cong)) ((dan than) OR (ban than)) cau~".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - thanh dung cua ((thong thong) or (tong cong)) ((dan than) OR (ban than)) cau*.