Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh huong
hieu soat » hieu suat, hieu hoat, hieu luat
tinh quan » trinh quan, tin quan, sinh quan
dung tan » dung toan, duong tan, dung tai
van hieu » cao hieu
van lien » van tien, van hien, va lien
tan van » tran van, tang van, dang van
lien so » lien son, bien so, lieu so

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung tan van hieu soat ) or ( ((tinh quan) or (tinh quang)) luan van lien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung tan van hieu soat ) OR ( ((tinh quan) OR (tinh quang)) luan van lien so )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung tan van hieu soat ) or ( ((tinh quan) or (tinh quang)) luan van lien so ))*.