Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
tai cuu » tai cuc, tai buu, tai cua
cam duc » cam xuc, cao duc, nam duoc
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
tang ma » mang may, tang van

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 ty ((tang ma) or (lang xa)) hoi. hieu va ((cam duc) OR (pham duc)) ban thanh tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((tang ma) OR (lang xa)) hoi. hieu va ((cam duc) OR (pham duc)) ban thanh tai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((tang ma) or (lang xa)) hoi. hieu va ((cam duc) OR (pham duc)) ban thanh tai cuu tre*".