Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu hoat, hieu luat
luan cao » juan cao, luan bao, quang cao
thi nang » thi cong, ki nang, thi hanh
suat hoi » luat hoi, sat hoi, suat khoa
hoi bien » hoa bien, hoi vien, voi 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 ( thi nang suat hoi bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung luan cao hieu soat ) OR ( thi nang suat hoi bien so )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung luan cao hieu soat ) or ( thi nang suat hoi bien so ))*.