Perhaps you should try some spelling variations:
quang thanh » quan thanh, hoang thanh, muong thanh
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
dung lan » dung luan, dung land, dung lam
van hieu » cao hieu
thanh va » thanh van, hanh va, thanh ha
lan van » luan van, lang van, tan van
tra » tran

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh dung lan van hieu suat ) or ( tinh quang thanh va ((kiem soat) or (kiem tra)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung lan van hieu suat ) OR ( tinh quang thanh va ((kiem soat) OR (kiem tra)) )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung lan van hieu suat ) or ( tinh quang thanh va ((kiem soat) or (kiem tra)) ))*.