Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trang » thanh trung, hanh trinh, minh trang
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
dan than » dan chan, ban than, dan toan
van than » van thanh, van thang, van tuan
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: hoc thieu xanh - ((hanh trang) OR (canh tranh)) va dung cong ((dan than) OR (van than)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - ((hanh trang) or (canh tranh)) va dung cong ((dan than) OR (van than)) cao~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - ((hanh trang) or (canh tranh)) va dung cong ((dan than) OR (van than)) cao*.