Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
cong tac » cong ty
tac than » tac thanh, tam than, tac nhan
than cao » toan cao, thai cao, than cap
va dang » van dang, va lang, da dang
va nang » van nang, da nang, cam nang

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 ((chieu xanh) OR (chieu sang)) - thanh cong ((va dang) OR (va nang)) cong tac than cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu xanh) or (chieu sang)) - thanh cong ((va dang) OR (va nang)) cong tac than cao~".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu xanh) or (chieu sang)) - thanh cong ((va dang) OR (va nang)) cong tac than cao*.