Perhaps you should try some spelling variations:
dung dand » dung danh, dung dang, dung land
hieu soat » hieu suat, hieu hoat, hieu luat
dung quan » dung quang, dung luan, luong quan
tien soat » trien hoat, thien hoat, kiem soat
dung dan » dung dat, dung san, tung dan
quan van » luan van, quan va, quan luan
van tien » toan tien, van hieu, van tuan

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 dan) or (dung dand)) cao hieu soat ) or ( trinh dung quan van tien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh ((dung dan) OR (dung dand)) cao hieu soat ) OR ( trinh dung quan van tien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh ((dung dan) or (dung dand)) cao hieu soat ) or ( trinh dung quan van tien soat ))*.