Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
hoc sach » hoc sinh, hoc cac, hoc anh
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cua triet, dua tren
cuc ban » cua ban, cac ban, cuu ban
cuu tre » cau tren, cau treo
dang ma » dang mau, dang mam, dang mat
tu dang » thu dang, tu dong, su dang
va cam » va cham, va cac, va cao
ma hoi » mai hoi, xa hoi, ma hoa
va co » vo co

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 co)) cuc ban thanh hai ((cua tre) OR (cuu 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 co)) cuc ban thanh hai ((cua tre) OR (cuu 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 co)) cuc ban thanh hai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: hoc sach tu dang ma hoi. hieu ((va cam) or (va co)) cuc ban thanh hai ((cua tre) OR (cuu tre))*.