Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tinh dat » tinh da, dinh dat, tinh dau
cac duc » cac du, cac dac, cac nuoc
dat cua » dai cua, day cua, mat cua
va tinh » may tinh
cao duc » dao duc, cao suc, giao duc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
sang xa » song xa, lang xa, sang ma
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 ve ((cac duc) OR (cao duc)) va tinh 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 ve ((cac duc) or (cao duc)) va tinh dat cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) y sang xa hoi. hieu ve ((cac duc) or (cao duc)) va tinh dat cua tre*.