Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
te sach » toc sach
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
cac duc » cac du, cao duc, cac dac
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
me hoi » le hoi
ve cac » va cac, vien cac

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 ky nang ((me hoi) or (ma hoa)). hieu ve cac duc ((ban thanh) OR (ban hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang ((me hoi) OR (ma hoa)). hieu ve cac duc ((ban thanh) OR (ban hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang ((me hoi) or (ma hoa)). hieu ve cac duc ((ban thanh) OR (ban hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang ((me hoi) or (ma hoa)). hieu ve cac duc ((ban thanh) OR (ban hanh)) hai cua tre*.