Perhaps you should try some spelling variations:
trinh quan » tinh quang, trinh luat, trinh han
hieu suat » hieu luat, hieu qua
tinh quan » tinh quang, tin quan, sinh quan
hien soat » thien hoat, kiem soat, bien soan
van hieu » cao hieu
van hien » van tien
tai van » thai van, thi van, tai san
luan » 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 tai van hieu suat ) or ( ((tinh quan) or (trinh quan)) luan van hien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung tai van hieu suat ) OR ( ((tinh quan) OR (trinh quan)) luan van hien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung tai van hieu suat ) or ( ((tinh quan) or (trinh quan)) luan van hien soat ))*.