Perhaps you should try some spelling variations:
tinh huong » dinh huong, anh huong
huong luan » huong lan, cuong luan, huong loan
quang tran » quang tuan, quang trung, quang thanh
hieu soat » hieu suat, hieu luat, kiem soat
hieu hoat » hieu hoa, thien hoat, hieu luat
van kiem » va kiem, van kien, van 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: (( tinh huong luan van ((hieu soat) OR (hieu hoat)) ) OR ( tinh quang tran van kiem tra ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh huong luan van ((hieu soat) OR (hieu hoat)) ) or ( tinh quang tran van kiem tra ))~".
• Adding a wildcard symbol may retrieve word variants: (( tinh huong luan van ((hieu soat) OR (hieu hoat)) ) or ( tinh quang tran van kiem tra ))*.