Perhaps you should try some spelling variations:
tinh huong » dinh huong, anh huong
huong luan » huong lan, cuong luan, huong loan
hieu soat » hieu hoat, hieu luat, hieu so
hieu suat » hieu luat, hieu qua
quang uan » quang tuan, quang ban, quang tran
kiem soat » kiem toan
van kiem » va kiem, van kien, van hieu
uan van » quan van, tan van, san van

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

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