Perhaps you should try some spelling variations:
trien hoat » tien hoa
tinh dung » trinh dung, tin dung, tinh quang
van trien » van tien, va trien, van tren
tinh quan » tinh quang, trinh quan, tin quan
hieu suat » hieu luat, hieu qua
dang van » hoang van, hang va
san van » tan van, tran van, phan van
luan » lan

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: (( tinh dung luan van trien hoat ) OR ( tinh quan ((san van) OR (dang van)) hieu suat ))~.
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van trien hoat ) or ( tinh quan ((san van) or (dang van)) hieu suat ))*.