Perhaps you should try some spelling variations:
dung lang » dung dang, dung nang, dung land
hieu suat » hieu luat, hieu qua
quang cua » quan cua, quang tuan, quang huy
kiem soat » kiem toan
lang van » dang van, tang van, hoang van
van hieu » cao hieu
cua va » cua vat, chua va, cua 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 lang van hieu suat ) or ( tinh quang cua va ((kiem soat) or (kiem tra)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung lang van hieu suat ) OR ( tinh quang cua va ((kiem soat) OR (kiem tra)) )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung lang van hieu suat ) or ( tinh quang cua va ((kiem soat) or (kiem tra)) ))*.