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 dieu » cong hieu, trong dieu, thong dieu
dong dieu » dang dieu, dong dien, dong hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) or (hieu lang)) - hanh doanh cua thong ((cong dieu) OR (dong dieu)) van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - hanh doanh cua thong ((cong dieu) OR (dong dieu)) van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) or (hieu lang)) - hanh doanh cua thong ((cong dieu) OR (dong dieu)) van ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu lang)) - hanh doanh cua thong ((cong dieu) OR (dong dieu)) van ban*.