Perhaps you should try some spelling variations:
doi chieu » doc hieu, ho chieu, mot chieu
cac duong » cau duong, cac tuong, cac dong
nguoi dan » nguoi dao, nguoi san, nguong dan
cac dung » cach dung, tac dung, cac dang
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap
doi chi » doi khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) OR (doi chi)) sang - canh tranh ((cac dung) or (cac duong)) nguoi dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doi chi)) sang - canh tranh ((cac dung) OR (cac duong)) nguoi dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doi chi)) sang - canh tranh ((cac dung) or (cac duong)) nguoi dan than cau".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doi chi)) sang - canh tranh ((cac dung) or (cac duong)) nguoi dan than cau*.