Perhaps you should try some spelling variations:
tinh huong » dinh huong, anh huong
huong luan » huong lan, cuong luan, huong loan
quang doan » quan doan, quang hoan, quang toan
hieu suat » hieu luat, hieu qua
kiem soat » kiem toan
van hieu » cao hieu
va kiem » van kien

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 suat ) OR ( tinh quang doan va kiem soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh huong luan van hieu suat ) OR ( tinh quang doan va kiem soat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh huong luan van hieu suat ) OR ( tinh quang doan va kiem soat ))*.