Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
qua cac » cua cac
cac tuc » cac toc, cac tu, cac tac
va hanh » van hanh, va thanh, va danh
hanh ca » hanh cac, hanh cat, hanh cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
me hoi » le hoi
tuc va » thuc va, truc va, tuc xa
ca cua » co cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ((me hoi) or (ma hoa)). hieu qua cac tuc va hanh ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((me hoi) OR (ma hoa)). hieu qua cac tuc va hanh ca cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((me hoi) or (ma hoa)). hieu qua cac tuc va hanh ca cua tre*.