Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
canh trinh » hanh trinh, canh tinh, anh trinh
hoc thieu » toc thieu, hoc hien
luan anh » luan danh, tuan anh, lan anh
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
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: hoc thieu xanh - ((canh trinh) or (canh tranh)) luan anh ((cong dan) OR (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - ((canh trinh) OR (canh tranh)) luan anh ((cong dan) OR (cong san)) toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - ((canh trinh) or (canh tranh)) luan anh ((cong dan) OR (cong san)) toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - ((canh trinh) or (canh tranh)) luan anh ((cong dan) OR (cong san)) toan cau*.