Perhaps you should try some spelling variations:
tinh huong » dinh huong, tinh quang
chien soat » thien hoat
hieu soat » hieu suat, hieu hoat, hieu luat
van chien » van hien, van tien
dung lam » dung luan, dung tai, dung dat
van hieu » cao hieu
lam van » lam san, nam van, dam 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: (( trinh dung lam van hieu soat ) OR ( ((tinh huong) OR (anh huong)) luan van chien soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( trinh dung lam van hieu soat ) or ( ((tinh huong) OR (anh huong)) luan van chien soat ))~".
• Adding a wildcard symbol may retrieve word variants: (( trinh dung lam van hieu soat ) or ( ((tinh huong) OR (anh huong)) luan van chien soat ))*.