Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
nang cong » nang song, dang cong, bang cong
hien anh » hien hanh, thien anh, dien anh
dien dan » hien dai, vien dai, gian dan
trinh va » trinh van, trinh vat, trinh ve
cong san » cong tac
chan cau » phan cau, chinh cau, nhanh cau
va nang » van nang, da nang, cam nang
can cau » van cau, ban cau, ca cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hien anh) or (dien dan)) - canh trinh va nang cong san ((chan cau) OR (can cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien anh) OR (dien dan)) - canh trinh va nang cong san ((chan cau) OR (can cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien anh) or (dien dan)) - canh trinh va nang cong san ((chan cau) OR (can cau))".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien anh) or (dien dan)) - canh trinh va nang cong san ((chan cau) OR (can cau))*.