Perhaps you should try some spelling variations:
doanh khoa » toan khoa
phan xuong » phan cong
khau thong » khau thuong, khap thong, khac thuong
cach thuc » anh thuc, cac thu
khau tong » khau cong, khau thuong, khac trong
sach tai » sach bai, sach tham, sach dao
tu doanh » su doanh, te doanh, ty doanh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((cach thuc) or (sach tai)) tu doanh khoa ((phan xuong) or (((khau thong) OR (khau tong))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((cach thuc) OR (sach tai)) tu doanh khoa ((phan xuong) OR (((khau thong) OR (khau tong))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((cach thuc) or (sach tai)) tu doanh khoa ((phan xuong) or (((khau thong) OR (khau tong))))*".