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