Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hieu lang » chieu sang, hieu quang, nhieu tang
tranh cua » doanh cua, manh cua
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
cong van » cong vang, cong san, song van
toan cao » toan tap
toan ban » van ban

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: theo ((hieu lang) OR (chieu xanh)) - canh tranh cua dung cong van ((toan cao) OR (toan ban))~.
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) or (chieu xanh)) - canh tranh cua dung cong van ((toan cao) or (toan ban))*.