Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
anh nang » ganh nang, anh bang, anh dang
nang vat » dang vat, bang vat, cang vat
vat dung » van dung, va dung, viet dung
cong tan » cong tac, cong san, cong thanh
toan tai » toan tap, doanh tai, toan cao
toan ban » van ban

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: theo ((chinh sach) OR (hieu lang)) - anh nang vat dung cong tan ((toan tai) OR (toan ban))~.
• Adding a wildcard symbol may retrieve word variants: theo ((chinh sach) or (hieu lang)) - anh nang vat dung cong tan ((toan tai) or (toan ban))*.