Perhaps you should try some spelling variations:
khanh luan » khanh thuan, doanh luan, hang luan
dung cong » dung trong
hoc hieu » hoc thieu, hoc hien, hoc dieu
doc hieu » toc thieu, hoc thieu, hoc hien
van dung » van dong, xay dung, tin dung
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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 hieu) OR (doc hieu)) lang - khanh luan van dung cong ((dan toan) OR (van toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc hieu) OR (doc hieu)) lang - khanh luan van dung cong ((dan toan) or (van toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: ((hoc hieu) OR (doc hieu)) lang - khanh luan van dung cong ((dan toan) or (van toan)) cau*.