Perhaps you should try some spelling variations:
dung quang » dang quang, dung quan, luong quang
hieu soat » hieu suat, hieu hoat, hieu luat
dien soan » bien soan, dien toan, dien hoa
van hieu » cao hieu
quang va » quang van, quan va, quang ma
va dien » va dieu, va lien, mai dien
luan » quan, lan

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 luan van hieu soat ) or ( tin dung quang va dien soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung luan van hieu soat ) OR ( tin dung quang va dien soan )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung luan van hieu soat ) or ( tin dung quang va dien soan ))*.