Perhaps you should try some spelling variations:
tinh phuong » trinh phuong, tinh huong, dinh phuong
phuong tan » phuong tran, phuong tay, phuong lan
tinh dung » trinh dung, tin dung, tinh quang
quan doan » quan hoang, chuan doan, chan doan
hieu suat » hieu luat, hieu qua
van hieu » cao hieu
quan va » quan vi, quan ha, luan va
tan van » tran van, tang van, luan van

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 ((quan doan) or (quan va)) hieu suat ) or ( tinh phuong tan van hieu suat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung ((quan doan) OR (quan va)) hieu suat ) OR ( tinh phuong tan van hieu suat )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung ((quan doan) or (quan va)) hieu suat ) or ( tinh phuong tan van hieu suat ))*.