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 hanh » va thanh, va danh, ban hanh
vai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
tu van » tu va
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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

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