Perhaps you should try some spelling variations:
dung thanh » duong thanh, dang thanh, dung thang
dong thanh » truong thanh
hieu soat » hieu suat, hieu hoat, hieu luat
tinh dung » trinh dung, tin dung, tinh quang
tien soat » trien hoat, thien hoat, kiem soat
van hieu » cao hieu
van tien » toan tien, van tuan
luan » quan, lan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin ((dung thanh) or (dong thanh)) van hieu soat ) or ( tinh dung luan van tien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin ((dung thanh) OR (dong thanh)) van hieu soat ) OR ( tinh dung luan van tien soat )).
• Adding a wildcard symbol may retrieve word variants: (( tin ((dung thanh) or (dong thanh)) van hieu soat ) or ( tinh dung luan van tien soat ))*.