Perhaps you should try some spelling variations:
quang tran » quang tuan, quang trung, quang thanh
huong luan » huong lan, cuong luan, huong loan
hieu suat » hieu luat, hieu qua
van kiem » va kiem, van kien, van hien
van hieu » cao hieu
luan va » luan van, luat va
va hieu » va dieu, va hien, cao hieu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( anh huong luan va hieu suat ) OR ( tinh quang tran ((van kiem) OR (van hieu)) soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( anh huong luan va hieu suat ) or ( tinh quang tran ((van kiem) OR (van hieu)) soat ))~".
• Adding a wildcard symbol may retrieve word variants: (( anh huong luan va hieu suat ) or ( tinh quang tran ((van kiem) OR (van hieu)) soat ))*.