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
sang xa » song xa, lang xa, sang ma
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
dat cua » dai cua, day cua, mat cua
cua tre » cua te, cuu tre, cua triet
y sang » _ sang, duy sang

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: ((te sach) OR (toc sach)) y sang xa hoi. hieu va cac duc ((va thanh) OR (ban thanh)) dat cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) y sang xa hoi. hieu va cac duc ((va thanh) OR (ban thanh)) dat cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y sang xa hoi. hieu va cac duc ((va thanh) OR (ban thanh)) dat cua tre*.