Perhaps you should try some spelling variations:
tien soat » trien hoat, thien hoat, kiem soat
quan tran » quang tran, quan tren, quan thanh
xuan tran » xuan trang, xuan toan, xuan tan
hieu soat » hieu suat, hieu hoat, hieu luat
van tien » toan tien, van tuan
van hieu » cao hieu
luan » lan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh dung luan van tien soat ) or ( tinh ((quan tran) OR (xuan tran)) van hieu soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung luan van tien soat ) OR ( tinh ((quan tran) OR (xuan tran)) van hieu soat ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( trinh dung luan van tien soat ) or ( tinh ((quan tran) OR (xuan tran)) van hieu soat ))*".