Perhaps you should try some spelling variations:
dung thanh » duong thanh, dong thanh, dang thanh
hieu soat » hieu suat, hieu hoat, hieu luat
thanh van » thanh san, thanh toan, thanh phan
tien soat » trien hoat, thien hoat, kiem soat
van hieu » cao hieu
van tien » toan tien, van tuan
tinh » dinh, minh, kinh

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

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