Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
nang co » nang cao, nang doc, nang noi
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
co hai » co dai, co hoi, o hai
so van » vo van
su van » tu van, vu van
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: toc sach y nang co hai. hieu van cac ((so van) OR (su van)) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang co hai. hieu van cac ((so van) OR (su van)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang co hai. hieu van cac ((so van) OR (su van)) hanh vi cua tre*.