Perhaps you should try some spelling variations:
sang quang » dang quang, hang quang, tang quang
trien hoat » tien hoa
tinh sang » tinh trang, trinh san, tinh son
quang van » quang ban, quan van, quang uan
van trien » van tien, va trien, van tren
tinh dung » trinh dung, tin dung, tinh huong
hieu suat » hieu luat, hieu qua
van hieu » cao hieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh sang quang van trien hoat ) or ( ((tinh dung) OR (tinh quang)) luan van hieu suat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh sang quang van trien hoat ) OR ( ((tinh dung) OR (tinh quang)) luan van hieu suat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh sang quang van trien hoat ) or ( ((tinh dung) OR (tinh quang)) luan van hieu suat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh sang quang van trien hoat ) or ( ((tinh dung) OR (tinh quang)) luan van hieu suat ))*.