Perhaps you should try some spelling variations:
dang quang » dung quang, nang quan, dang hung
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu hoat, hieu luat
tinh dang » binh dang, tinh sang, dinh dang
quang ban » quang binh, quang tuan, quang tran
hien soat » thien hoat, kiem soat, bien soan
van hieu » cao hieu
ban hien » van hien, han hien, ban dien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung (luan OR lan) van hieu soat ) or ( tinh dang quang ban hien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung (luan OR lan) van hieu soat ) OR ( tinh dang quang ban hien soat )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung (luan OR lan) van hieu soat ) or ( tinh dang quang ban hien soat ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung (luan OR lan) van hieu soat ) or ( tinh dang quang ban hien soat ))*.