Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
thanh dung » thanh duong, thanh tung, thanh hung
hieu manh » hieu nganh, dieu hanh, hien hanh
va thong » va thuong, va phuong, he thong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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: doc ((hieu manh) OR (chieu xanh)) - thanh dung va thong thong ((dan toan) OR (dan than)) tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu manh) or (chieu xanh)) - thanh dung va thong thong ((dan toan) OR (dan than)) tap~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu manh) or (chieu xanh)) - thanh dung va thong thong ((dan toan) OR (dan than)) tap*.