Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
thu sach » thuat sach, thuoc sach, thu hoach
tham duc » pham duc, tham du, than duc
tai cua » thai cua, tai cuc, tri cua
duc ban » duc tan, duc van, dua ban
va tham » van tham, va cham, va thanh
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
tang ma » mang may, tang van
tu sach » su sach, te sach, tu cach
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((thu sach) OR (tu sach)) tu ((tang ma) or (lang xa)) hoi. hieu va tham duc ban thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (tu sach)) tu ((tang ma) OR (lang xa)) hoi. hieu va tham duc ban thanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) OR (tu sach)) tu ((tang ma) or (lang xa)) hoi. hieu va tham duc ban thanh tai cua tre*".