Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van thanh » van tuan
van dung » van dong, xay dung, tin dung
nam truc » nam truoc, nam thuc, nam trung
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve nam » he nam, va nam, le nam
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((van dung) or (tran quang)) x ho. hieu ve nam truc ((van thanh) OR (ban thanh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((van dung) OR (tran quang)) x ho. hieu ve nam truc ((van thanh) OR (ban thanh)) de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((van dung) or (tran quang)) x ho. hieu ve nam truc ((van thanh) OR (ban thanh)) de cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((van dung) or (tran quang)) x ho. hieu ve nam truc ((van thanh) OR (ban thanh)) de cua tre*.