Perhaps you should try some spelling variations:
dinh huong » dinh duong, anh huong
huong luan » huong lan, cuong luan, huong loan
hieu suat » hieu luat, hieu qua
quang ban » quang binh, quang tuan, quang tran
kien soat » kiem soat, bien soan, kien hoa
van kien » van tien, van hien, van chien
ban van » ban dan, ban va, tan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( dinh huong luan van ((thieu so) or (hieu suat)) ) or ( tinh quang ban van kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( dinh huong luan van ((thieu so) OR (hieu suat)) ) OR ( tinh quang ban van kien soat )).
• Adding a wildcard symbol may retrieve word variants: (( dinh huong luan van ((thieu so) or (hieu suat)) ) or ( tinh quang ban van kien soat ))*.