Perhaps you should try some spelling variations:
doanh doanh » doanh hoan, doanh thanh, dong doanh
thieu sang » chieu sang, thieu khang, thieu quang
quan trong » gian trong
hoc thieu » toc thieu, hoc hien
tuan phan » luan phan, toan phan, than phan
tuan pham » thanh pham, san pham, tac pham
toan » tran

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: hoc thieu sang - ((doanh doanh) OR (toan doanh)) quan trong cong ((tuan phan) OR (tuan pham)) cac~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - ((doanh doanh) or (toan doanh)) quan trong cong ((tuan phan) OR (tuan pham)) cac~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - ((doanh doanh) or (toan doanh)) quan trong cong ((tuan phan) OR (tuan pham)) cac*.