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