Perhaps you should try some spelling variations:
tinh dung » trinh dung, tinh quang, tinh huong
hieu suat » hieu luat, hieu qua
quang hoi » quang huy, quan doi, quang tri
van hieu » cao hieu
tin nang » ki nang, thi nang, van nang
hoi bien » hoa bien, hoi vien, voi bien
bien so » bien doi
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 suat ) or ( ((tin nang) or (tin dung)) quang hoi bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan van hieu suat ) OR ( ((tin nang) OR (tin dung)) quang hoi bien so )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van hieu suat ) or ( ((tin nang) or (tin dung)) quang hoi bien so ))*.