Perhaps you should try some spelling variations:
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
van anh » van thanh, tuan anh, van minh
vai cua » hai cua, lai cua, bai 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 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 can ky nang o hai. hieu va cac tuc ((va hanh) or (van anh)) ((vai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can ky nang o hai. hieu va cac tuc ((va hanh) OR (van anh)) ((vai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu can ky nang o hai. hieu va cac tuc ((va hanh) or (van anh)) ((vai cua) or (dai cua)) tre*.