Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu luat, kiem soat
hieu hoat » hieu hoa, thien hoat, hieu luat
hanh suat » hanh sua, hanh luat, nang suat
luan cao » juan cao, luan bao, quang cao
thi hanh » thi thanh
suat voi » sat voi, sua voi, sua doi
voi bien » vat bien, va bien, ve bien
bien so » bien doi

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 cao ((hieu soat) OR (hieu hoat)) ) or ( thi hanh suat voi bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan cao ((hieu soat) OR (hieu hoat)) ) OR ( thi hanh suat voi bien so )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung luan cao ((hieu soat) OR (hieu hoat)) ) or ( thi hanh suat voi bien so ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan cao ((hieu soat) OR (hieu hoat)) ) or ( thi hanh suat voi bien so ))*.