Perhaps you should try some spelling variations:
tinh dung » trinh dung, tinh quang, tinh huong
hieu suat » hieu luat, hieu qua
dung dat » dung va, dung tai
cuu bien » cua bien, che bien, cam bien
binh tin » binh tinh, binh tan, dinh tin
dung van » duong van, dung va, dang van
van hieu » cao hieu
dat cuu » dat cau, dat cua
bien va » dien va, tien va, vien va

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 dat cuu bien va ) or ( binh tin dung van hieu suat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung dat cuu bien va ) OR ( binh tin dung van hieu suat ))*.