Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
canh doanh » hanh doanh, chinh doanh, doanh doanh
hieu sang » chieu sang, hieu lang, nhieu tang
doanh cua » doanh luan
cua thong » cua thuong, cua khong, cua tong
manh toan » thanh toan, anh tuan, tinh toan
dan toan » van toan, dan than, xuan toan

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 ((hieu sang) OR (hieu quang)) - canh doanh cua thong thong ((dan toan) OR (manh toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu quang)) - canh doanh cua thong thong ((dan toan) or (manh toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu quang)) - canh doanh cua thong thong ((dan toan) or (manh toan)) cau*.