Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh huong
hieu hoat » hieu hoa, thien hoat, hieu luat
quang uan » quang tuan, quang ban, quang tran
hieu soan » hieu toan, hieu van, bien soan
hieu suat » hieu luat, hieu qua
van hieu » cao hieu
uan van » quan van, tan van, san van
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: (( tinh dung luan van hieu hoat ) or ( tinh quang uan van ((hieu soan) or (hieu suat)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan van hieu hoat ) OR ( tinh quang uan van ((hieu soan) OR (hieu suat)) )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van hieu hoat ) or ( tinh quang uan van ((hieu soan) or (hieu suat)) ))*.