Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hieu manh » hieu nganh, hien hanh, hieu van
tranh qua » tranh cua, thanh qua, trinh qua
dung cong » dung trong
qua dung » quang dung, su dung, qua song
than cao » toan cao, thai cao, than cap
cong tu » cong ty, cong cu, dong tu
tu than » tu thanh, tu nhan, nu than

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: hoc ((((hieu manh) OR (dieu hanh))) OR (chieu xanh)) - canh tranh qua dung cong tu than cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((((hieu manh) OR (dieu hanh))) or (chieu xanh)) - canh tranh qua dung cong tu than cao~".
• Adding a wildcard symbol may retrieve word variants: hoc ((((hieu manh) OR (dieu hanh))) or (chieu xanh)) - canh tranh qua dung cong tu than cao*.