Perhaps you should try some spelling variations:
hanh doanh » hang doanh, chinh doanh, doanh doanh
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
doanh cua » doanh luan
cua thong » cua thuong, cua khong, cua tong
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
tran tap » toan tap, tran tan, tran tuan

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: doc ((chieu sang) OR (hieu lang)) - hanh doanh cua thong ((cong tan) OR (cong san)) tran tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((chieu sang) OR (hieu lang)) - hanh doanh cua thong ((cong tan) or (cong san)) tran tap~".
• Adding a wildcard symbol may retrieve word variants: doc ((chieu sang) OR (hieu lang)) - hanh doanh cua thong ((cong tan) or (cong san)) tran tap*.