Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
nang co » nang cao, nang doc, nang noi
van cau » van dau, van hau, van chat
cac ban » cac dan, can ban, cac bai
cac van » cac dan
cua tre » cua te, cuu tre, cua triet
nang o » nang ho, nang ro, nang x
vi cua » vai cua, di cua

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) or (nang co)) hai. hieu van cau ((cac ban) OR (cac van)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cac ky ((nang o) OR (nang co)) hai. hieu van cau ((cac ban) OR (cac van)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cac ky ((nang o) or (nang co)) hai. hieu van cau ((cac ban) OR (cac van)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu cac ky ((nang o) or (nang co)) hai. hieu van cau ((cac ban) OR (cac van)) hanh vi cua tre*.