Perhaps you should try some spelling variations:
quang quang » quan quang, dang quang, dung quang
trien hoat » tien hoa
tinh dung » trinh dung, tin dung, tinh huong
hieu suat » hieu luat, hieu qua
quang van » quang ban, quan van, quang uan
tien soat » thien hoat, kiem soat, tien hoa
van hieu » cao hieu
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 ( tinh quang quang van ((tien soat) OR (trien hoat)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan van hieu suat ) OR ( tinh quang quang van ((tien soat) OR (trien hoat)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung luan van hieu suat ) or ( tinh quang quang van ((tien soat) OR (trien hoat)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van hieu suat ) or ( tinh quang quang van ((tien soat) OR (trien hoat)) ))*.