Perhaps you should try some spelling variations:
luong quang » luong quan
dung quang » dang quang, dung quan, dung ung
hieu soat » hieu suat, hieu hoat, hieu luat
van hieu » cao hieu
van kien » van tien, van hien, van chien
kien hoa » dien hoa, tien hoa, kien ha
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: (( trinh dung luan van hieu soat ) or ( tinh ((dung quang) or (luong quang)) van kien hoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung luan van hieu soat ) OR ( tinh ((dung quang) OR (luong quang)) van kien hoa )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung luan van hieu soat ) or ( tinh ((dung quang) or (luong quang)) van kien hoa ))*.