Perhaps you should try some spelling variations:
hanh trang » thanh trung, hanh trinh, minh trang
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quan » hieu qua, lieu quan, thien quan
dung cong » dung trong
vat dung » van dung, va dung, viet dung
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao 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: ho ((chieu sang) OR (hieu quan)) - ((hanh trang) OR (canh tranh)) vat dung cong dan van ban~.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quan)) - ((hanh trang) or (canh tranh)) vat dung cong dan van ban*.