Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
va danh » va dinh, va dan, va hanh
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

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