Perhaps you should try some spelling variations:
te sach » toc sach
cac ban » cac dan, cac van, can ban
cuc ban » cua ban, cuu ban, duc ban
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
nang o » nang co, nang ho, nang ro
vi cua » vai cua, di cua
ve cac » va cac, vien cac
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: ((te sach) or (su sach)) ky nang o hoi. hieu ve cac ((cuc ban) or (cac ban)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (su sach)) ky nang o hoi. hieu ve cac ((cuc ban) OR (cac ban)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (su sach)) ky nang o hoi. hieu ve cac ((cuc ban) or (cac ban)) hanh vi cua tre*.