Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
dung quan » dung quang, dung luan, luong quan
hieu suat » hieu luat, hieu qua
khoa bien » hoa bien, khoa tieng, khoa dieu
quan cao » quang cao, quan cau, quan ao
thi nang » thi cong, ki nang, thi hanh
nang da » nang dau, nang dua, nang dan
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 quan cao hieu suat ) or ( thi nang da khoa bien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung quan cao hieu suat ) OR ( thi nang da khoa bien so ))*.