Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
phan hieu » van hieu, phan kien, gian hieu
hieu lang » chieu sang, hieu quang, nhieu tang
quan hang » quan hoang, quan lang, quan hanh
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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: phan hieu lang - ((hanh trinh) OR (canh tranh)) quan hang ((cong dan) OR (cong san)) toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "phan hieu lang - ((hanh trinh) or (canh tranh)) quan hang ((cong dan) OR (cong san)) toan cau~".
• Adding a wildcard symbol may retrieve word variants: phan hieu lang - ((hanh trinh) or (canh tranh)) quan hang ((cong dan) OR (cong san)) toan cau*.