Perhaps you should try some spelling variations:
luong quang » luong quan
dung quang » dang quang, dung quan, dung ung
thanh kien » thanh vien, thanh nien, thanh hien
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu hoat, hieu luat
kien soat » kiem soat, bien soan, kien 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 soat ) or ( tinh ((luong quang) OR (dung quang)) thanh kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan van hieu soat ) OR ( tinh ((luong quang) OR (dung quang)) thanh kien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung luan van hieu soat ) or ( tinh ((luong quang) OR (dung quang)) thanh kien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan van hieu soat ) or ( tinh ((luong quang) OR (dung quang)) thanh kien soat ))*.