Perhaps you should try some spelling variations:
dung quang » dang quang, dung quan, luong quang
quang van » quang ban, quan van, quang uan
kiem soat » kiem toan
van hieu » cao hieu
danh duy » manh duy, danh du, dinh duy
van kiem » va kiem, van kien, van hien
duy van » duy vat, dung van

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 quang van hieu qua ) or ( minh danh duy van kiem soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung quang van hieu qua ) OR ( minh danh duy van kiem soat ))*.