Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
te sach » toc sach
sach tu » sach thu, cach tu, sach ty
tu cong » thu cong, te cong, tai cong
cong xa » cong xay, cong xua, cong ha
xa vanh » xa vinh, xa van, xa thanh
cua tre » cua te, cuu tre, cua triet
va cao » va co, va bao
va dao » ca dao
duc xa » duoc xa, tuc xa, duc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu cong xa hoi. hieu ((((va cao) or (va cac))) or (va dao)) duc xa vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu cong xa hoi. hieu ((((va cao) OR (va cac))) OR (va dao)) duc xa vanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach tu cong xa hoi. hieu ((((va cao) or (va cac))) or (va dao)) duc xa vanh dai cua tre*.