Perhaps you should try some spelling variations:
hieu suat » hieu luat, hieu qua
dung quan » dung quang, dung luan, luong quan
tien soan » bien soan, tien hoang, thien toan
dung chi » dung cho, dung chien, chung chi
dung thi » dung tai, dung tri, dung thu
van hieu » cao hieu
quan van » luan van, quan va, quan luan
van tien » toan tien, 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: (( tin ((dung chi) or (dung thi)) van hieu suat ) or ( tin dung quan van tien soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin ((dung chi) OR (dung thi)) van hieu suat ) OR ( tin dung quan van tien soan )).
• Adding a wildcard symbol may retrieve word variants: (( tin ((dung chi) or (dung thi)) van hieu suat ) or ( tin dung quan van tien soan ))*.