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
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
cam tu » nam tu, dam tu, tam tu

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 xa 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 xa hoi. hieu ve ((cam tu) OR (cam thu)) van thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) tay tang xa 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 xa hoi. hieu ve ((cam tu) OR (cam thu)) van thanh dai cua tre*.