Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
van thanh » ban thanh, van tuan
van nang » van quang, van dong, van dung
tu sach » thu sach, su sach, te sach
van cac » van hac, van bac, dan cac
van cau » van dau, van hau, van chat
cac van » cac dan
cua tre » cua te, cuu tre, cua triet
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((van nang) or (van ban)) o hoi. hieu ((van cac) OR (van cau)) cac van thanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((van nang) OR (van ban)) o hoi. hieu ((van cac) OR (van cau)) cac van thanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((van nang) or (van ban)) o hoi. hieu ((van cac) OR (van cau)) cac van thanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((van nang) or (van ban)) o hoi. hieu ((van cac) OR (van cau)) cac van thanh dai cua tre*.