Perhaps you should try some spelling variations:
hieu suat » hieu luat, hieu qua
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
tin » tinh

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 luan cao hieu suat ) or ( thi hanh suat voi bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung luan cao hieu suat ) OR ( thi hanh suat voi bien so )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung luan cao hieu suat ) or ( thi hanh suat voi bien so ))*.