Perhaps you should try some spelling variations:
tinh huong » dinh huong, tinh quang, anh huong
tinh luong » dinh luong, minh luong, tinh cuong
hieu suat » hieu luat, hieu qua
bien soan » bien so
van hieu » cao hieu
quan van » quan va, quan luan, quan doan
van bien » van tien, van hien, vat bien
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 hieu suat ) or ( ((tinh luong) or (tinh huong)) quan van bien soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung luan van hieu suat ) OR ( ((tinh luong) OR (tinh huong)) quan van bien soan )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung luan van hieu suat ) or ( ((tinh luong) or (tinh huong)) quan van bien soan ))*.