Perhaps you should try some spelling variations:
cong doanh » cong danh, cong doan, dong doanh
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
dang cong » dung cong
doanh van » doan van, doanh va, doanh ban
anh tang » anh bang, anh nang, anh sang
anh dang » anh dong, anh dung, anh bang
cua dang » cua cong, cua 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: ho ((hieu lang) OR (chieu sach)) - ((anh tang) OR (anh dang)) cua dang cong doanh van ban~.
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chieu sach)) - ((anh tang) or (anh dang)) cua dang cong doanh van ban*.