Perhaps you should try some spelling variations:
thanh hien » thanh vien, thanh nien, thanh huyen
quan thanh » ban thanh, van thanh
hieu luat » hieu qua
tinh dung » trinh dung, tinh quang, tinh huong
dung quan » dung quang, dung luan, luong quan
dung dat » dung va, dung tai
chi hieu » cao hieu, chi tiet, co hieu
dat chi » dat cho, dat thi, dau chi
hien so » khien so, bien so, hieu so

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 dat chi hieu luat ) or ( tinh dung quan thanh hien so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung dat chi hieu luat ) OR ( tinh dung quan thanh hien so ))*.