Perhaps you should try some spelling variations:
nhung tuong » nhung phuong, hung vuong, nhung cong
nhung huong » nhung phuong, nhung cong, nhung dung
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
tranh cua » doanh cua, manh cua
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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: hoc thieu sang - canh tranh cua ((nhung huong) OR (nhung tuong)) ((dan toan) OR (van toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - canh tranh cua ((nhung huong) or (nhung tuong)) ((dan toan) OR (van toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - canh tranh cua ((nhung huong) or (nhung tuong)) ((dan toan) OR (van toan)) cau*.