Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
tien soat » trien hoat, thien hoat, kiem soat
tinh quan » tinh quang, trinh quan, tin quan
hieu suat » hieu luat, hieu qua
van tien » toan tien, van hieu, van tuan
san van » tran van, dang van, phan van
tan van » tran van, tang van, dang 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 tien soat ) OR ( tinh quan ((san van) OR (tan van)) hieu suat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung luan van tien soat ) or ( tinh quan ((san van) OR (tan van)) hieu suat ))~".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van tien soat ) or ( tinh quan ((san van) OR (tan van)) hieu suat ))*.