Perhaps you should try some spelling variations:
doanh doanh » toan doanh, doanh hoan, doanh thanh
hieu lang » chieu sang, hieu quang, nhieu tang
doanh cua » doanh luan
cua thang » cua hang, cua thanh, xua thang
hoc hieu » hoc thieu, hoc hien, doc hieu
nong dan » nong san, nguong dan, huong dan
cong dan » cong san, cong tan, huong dan
than man » than ma, thanh san, tran manh

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - doanh doanh cua thang ((nong dan) OR (cong dan)) than man~".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - doanh doanh cua thang ((nong dan) OR (cong dan)) than man*.