Perhaps you should try some spelling variations:
nhung dong » nhung don, nhung cong, nhung dung
hieu quang » thieu quang, hieu quan, hieu qua
cua nhung » va nhung
doan phan » doanh phan, dan phan, doanh nhan
toan phan » thanh phan, toan ban, hoa phan
doc hieu » toc thieu, hoc thieu, hoc hien
van manh » van minh, van anh, van hanh

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 quang - ((van manh) OR (cach mang)) cua nhung dong ((doan phan) OR (toan phan)) tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu quang - ((van manh) or (cach mang)) cua nhung dong ((doan phan) OR (toan phan)) tu~".
• Adding a wildcard symbol may retrieve word variants: doc hieu quang - ((van manh) or (cach mang)) cua nhung dong ((doan phan) OR (toan phan)) tu*.