Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
ngu phuong » ngu thuong, nhu phuong, ngu chuong
danh toan » manh toan, anh toan, dang toan
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
dan toan » van toan, dan than, manh toan

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) OR (theo chieu)) xanh - canh tranh va ngu phuong ((danh toan) OR (dan toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (theo chieu)) xanh - canh tranh va ngu phuong ((danh toan) OR (dan toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (theo chieu)) xanh - canh tranh va ngu phuong ((danh toan) OR (dan toan)) cau*.