Perhaps you should try some spelling variations:
dung ltang » dung luan, dung thang, dung khang
dung quang » dang quang, dung quan, luong quang
quang tang » quang thang, quang dang, quang tung
hieu suat » hieu luat, hieu qua
hien soat » thien hoat, kiem soat, bien soan
van hieu » cao hieu
tang van » dang van, hoang van, trong van
van hien » van tien

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 ltang) OR (dung quang)) van hieu suat ) or ( tinh quang tang van hien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh ((dung ltang) OR (dung quang)) van hieu suat ) OR ( tinh quang tang van hien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh ((dung ltang) OR (dung quang)) van hieu suat ) or ( tinh quang tang van hien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh ((dung ltang) OR (dung quang)) van hieu suat ) or ( tinh quang tang van hien soat ))*.