Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hoc sach » hoc sinh, hoc cac, hoc anh
hoi cua » hoi chuc
hai cua » thai cua, dai cua, lai cua
cuc ban » cua ban, cac ban, cuu ban
sach tu » sach thu, cach tu, sach ty
dang ma » dang mau, dang mam, dang mat
tu dang » thu dang, tu dong, su dang
va cao » va cac, va co, va dao
va cam » va cham, va cac, va cai
ma hoi » mai hoi, xa hoi, ma hoa

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

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