Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
hanh tranh » hanh trinh, hanh trang, lanh tranh
nhung cong » dung cong, thong cong, hang cong
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (theo chieu)) xanh - ((hanh tranh) OR (canh tranh)) va nhung cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (theo chieu)) xanh - ((hanh tranh) OR (canh tranh)) va nhung cong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (theo chieu)) xanh - ((hanh tranh) OR (canh tranh)) va nhung cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (theo chieu)) xanh - ((hanh tranh) OR (canh tranh)) va nhung cong dan toan cau*.