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
cong tuan » cong tan, cong luan, cong thanh
tuan phan » luan phan, toan phan, tuan pham
phan dau » phan tu, hang dau
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 dau~.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - ((doanh doanh) or (toan doanh)) quan trong cong tuan phan dau*.