Perhaps you should try some spelling variations:
doanh doanh » toan doanh, doanh hoan, doanh thanh
chieu sach » chinh sach, chiet tach, chieu sang
hieu lang » chieu sang, hieu quang, nhieu tang
doanh cua » doanh luan
cua thong » cua thuong, cua khong, cua tong
thong tan » thong than, thong tran, thong tin
tan van » tran van, tang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu lang)) - doanh doanh cua thong thong tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - doanh doanh cua thong thong tan van ban*.