Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
trinh cua » tinh cua, trinh luat, trinh quan
ban cong » bang cong, van cong, phan cong
cong san » cong tac
toan cau » toan cao, toan tap, toan tai
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: doc ((hieu sang) OR (hieu lang)) - hanh trinh cua ban cong san ((toan cau) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sang) OR (hieu lang)) - hanh trinh cua ban cong san ((toan cau) or (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) OR (hieu lang)) - hanh trinh cua ban cong san ((toan cau) or (toan ban))*.