Perhaps you should try some spelling variations:
tinh dung » trinh dung, tinh quang, tinh huong
dung quan » dung quang, luong quan, dang quang
hieu soat » hieu suat, hieu hoat, hieu luat
van hien » van tien
hien tra » hien trau, hien ra, hien trang
quan van » quan va, quan luan, quan doan
van hieu » cao hieu
luan » 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 luan van hien tra ) or ( tinh dung quan van hieu soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung luan van hien tra ) OR ( tinh dung quan van hieu soat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung luan van hien tra ) or ( tinh dung quan van hieu soat ))*.