Perhaps you should try some spelling variations:
tinh huong » dinh huong, anh huong
huong luan » huong lan, cuong luan, huong loan
thien hoat » trien hoat, thien thuat, tien hoa
hieu suat » hieu luat, hieu qua
quang uan » quang tuan, quang ban, quang tran
hien soat » kiem soat, bien soan, hien luat
van hieu » cao hieu
uan van » quan van, tan van, san van

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 suat ) OR ( tinh quang uan van ((hien soat) OR (thien hoat)) ))~.
• Adding a wildcard symbol may retrieve word variants: (( tinh huong luan van hieu suat ) or ( tinh quang uan van ((hien soat) or (thien hoat)) ))*.