Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, va tinh, le thanh
hieu van » hieu va, thien van, lieu va
van cac » van hac, van cau, van bac
cac dac » cac dan, cac dai, cac bac
ty hang » ly hang, thi hang, thu hang
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ty hang) OR (ty xang)) x hoi. hieu van cac dac ((va thanh) or (ban thanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty hang) OR (ty xang)) x hoi. hieu van cac dac ((va thanh) OR (ban thanh)) dai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty hang) OR (ty xang)) x hoi. hieu van cac dac ((va thanh) or (ban thanh)) dai cua tre*".