Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
mai khoi » mai khoa, tai khoa, cac khoi
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va cam » va cham, va cao, va cai
xuc va » duc va, tuc va, luc va
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((xa hoi) OR (mai khoi)). hieu ((va cam) OR (va cac)) xuc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang ((xa hoi) or (mai khoi)). hieu ((va cam) OR (va cac)) xuc va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((xa hoi) or (mai khoi)). hieu ((va cam) OR (va cac)) xuc va hanh vi cua tre*.