Perhaps you should try some spelling variations:
ban banh » ban hanh, ban danh, ban thanh
tu sach » thu sach, su sach, te sach
hai cua » thai cua, dai cua, hoi cua
ban anh » ban hanh, ban danh, bang anh
cam duc » cam xuc, cao duc, pham duc
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty ((nang xa) or (nang ma)) hoi. hieu va cam duc ((ban banh) OR (ban anh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. hieu va cam duc ((ban banh) OR (ban anh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (nang ma)) hoi. hieu va cam duc ((ban banh) OR (ban anh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. hieu va cam duc ((ban banh) OR (ban anh)) hai cua tre*.