Perhaps you should try some spelling variations:
quang dung » quang trung, ung dung, cuong dung
hieu suat » hieu luat, hieu qua
dung van » duong van, dung va, dang van
van hieu » cao hieu
dinh dan » dinh dang, dinh duan, dinh van
dan luan » doanh luan, dung luan, tang luan
de thanh » le thanh
tinh » trinh, minh, kinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh quang dung van hieu suat ) or ( dinh dan luan van de thanh ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quang dung van hieu suat ) OR ( dinh dan luan van de thanh ))*.