Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh dai » thanh hai, thanh tai, thanh dat
toc sach » hoc sach, doc sach, thuoc sach
tay tang » tay lang, tay trung, tay quang
cam thu » nam thu, cac thu, ca thu
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
cam tu » nam tu, dam tu, tam tu
ma hoi » mai hoi, xa hoi, ma hoa

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) or (toc sach)) tay tang ma hoi. hieu ve ((cam tu) or (cam thu)) van thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tay tang ma hoi. hieu ve ((cam tu) OR (cam thu)) van thanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) tay tang ma hoi. hieu ve ((cam tu) or (cam thu)) van thanh dai cua tre*.