Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh cac » hanh cac, thanh bac, thanh ca
nam thuc » nam thuoc, nam thu, nam tu
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
thi van » thi lan, thi hanh, thi nang
cac cua » cach cua, cac qua, ca cua
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: so sach ty ((nang xa) or (lang xa)) hoi. thi van ((nam thuc) OR (am thuc)) ban thanh cac cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (lang xa)) hoi. thi van ((nam thuc) OR (am thuc)) ban thanh cac cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) or (lang xa)) hoi. thi van ((nam thuc) OR (am thuc)) ban thanh cac cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((nang xa) or (lang xa)) hoi. thi van ((nam thuc) OR (am thuc)) ban thanh cac cua tre*.