Perhaps you should try some spelling variations:
tinh dung » trinh dung, tinh quang, tinh huong
hieu soat » hieu suat, hieu hoat, hieu luat
dung lam » dung tai, dung dat, dung ha
van kiem » va kiem, van hien, tac kiem
van kien » van tien, van hien, van chien
van hieu » cao hieu
luan » quan, lan

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

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