Perhaps you should try some spelling variations:
ban hanh » ban hang
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
bai cua » ban cua, dai cua, bai ca
hai cua » thai cua, dai cua, hoi cua
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cac ky nang o hoc. hieu va cac tuc ((va hanh) or (ban hanh)) ((bai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky nang o hoc. hieu va cac tuc ((va hanh) OR (ban hanh)) ((bai cua) OR (hai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu cac ky nang o hoc. hieu va cac tuc ((va hanh) or (ban hanh)) ((bai cua) or (hai cua)) tre*.