Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
hieu manh » chieu xanh, hieu nganh, dieu hanh
canh manh » lanh manh, canh tranh, cach mang
cua dung » cua dang, qua dung, cua rung
cua dong » chua dong, cua cong, cua dang
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: hoc ((hieu manh) or (thien thanh)) - canh manh ((cua dung) OR (cua dong)) huong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (thien thanh)) - canh manh ((cua dung) OR (cua dong)) huong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (thien thanh)) - canh manh ((cua dung) OR (cua dong)) huong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu manh) or (thien thanh)) - canh manh ((cua dung) OR (cua dong)) huong dan toan cau*.