Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh hoai
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh do » thanh de, thanh pho, thanh hoa
sach ky » sac ky, sach y, sach ty
thu day » thuc day, thu da, thu dac
cua tre » cua te, cuu tre, cua triet
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang x hoi. hieu van nam thu day ((thanh doi) or (thanh do)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang x hoi. hieu van nam thu day ((thanh doi) OR (thanh do)) cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang x hoi. hieu van nam thu day ((thanh doi) or (thanh do)) cua tre*.