Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu lang » chieu sang, hieu quang, nhieu tang
vat dung » van dung, viet dung, mat duong
dan than » ban than, van than, dan toan
dan chan » dan gian, dan ca, van chat
ho hieu » ho chieu, hoi hieu, nho hieu
va dung » van dung, va duong, va ung

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