Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh tai » thanh hai, thanh toan, doanh tai
sach tu » sach thu, cach tu, sach ty
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
qua cac » cua cac
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
du ban » dua ban, duc ban, du bao

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 y) or (sach tu)) ((tang ma) or (lang xa)) hoi. hieu qua cac du ban thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach y) OR (sach tu)) ((tang ma) OR (lang xa)) hoi. hieu qua cac du ban thanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sach tu)) ((tang ma) or (lang xa)) hoi. hieu qua cac du ban thanh tai cua tre*.