Perhaps you should try some spelling variations:
dinh quan » dinh quang, dinh xuan, dinh duan
hieu luat » hieu qua
tinh nang » trinh nang, tin nang, tich nang
hien soat » thien hoat, kiem soat, bien soan
van hieu » cao hieu
suat van » suat va, sat van, suat nang
van hien » van tien
tri van » thi van, tri va, trinh van

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( dinh quan tri van hieu luat ) OR ( tinh nang suat van hien soat ))~.
• Adding a wildcard symbol may retrieve word variants: (( dinh quan tri van hieu luat ) or ( tinh nang suat van hien soat ))*.