Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
cac duc » cac du, cao duc, cac dac
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
ty hang » ly hang, thi hang, thu hang
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) ((ty hang) OR (ty xang)) x hoi. hieu van cac duc va thanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (hoc sach)) ((ty hang) or (ty xang)) x hoi. hieu van cac duc va thanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (hoc sach)) ((ty hang) or (ty xang)) x hoi. hieu van cac duc va thanh dai cua tre*.