Perhaps you should try some spelling variations:
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
tang nguoi » thang nguoi, tang nguon, nang nguoi
tranh cua » doanh cua, manh cua
cua tang » cua dang, cua hang, ca tang
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: hoc ((thieu xanh) OR (chieu xanh)) - canh tranh cua tang nguoi ((dan toan) OR (dan than)) tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - canh tranh cua tang nguoi ((dan toan) or (dan than)) tap~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - canh tranh cua tang nguoi ((dan toan) or (dan than)) tap*.