Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va cao » va co, va dao, va bao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) y nang xa hoi. lieu ((va cao) OR (va cac)) thuc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y nang xa hoi. lieu ((va cao) OR (va cac)) thuc va hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) y nang xa hoi. lieu ((va cao) OR (va cac)) thuc va hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y nang xa hoi. lieu ((va cao) OR (va cac)) thuc va hanh vai cua tre*.