Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
hoi hieu » hoi phieu, hoi tieu, moi hieu
quan ban » quang ban, qua ban, quan van
ban cong » bang cong, van cong, phan cong
cong tac » cong ty
tac tra » tac trai, tac tren
tra cau » tra sau, ta cau, tra cuu

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - ((hanh trinh) or (canh tranh)) quan ban cong tac tra cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - ((hanh trinh) OR (canh tranh)) quan ban cong tac tra cau*.