Perhaps you should try some spelling variations:
ban hanh » ban hang
sach doi » sach hoi, sach dao, sach bai
hieu van » hieu va, thien van, lieu va
sach moi » sach hoi, bach mai, sach bai
van cam » van nam, van lam, van cau
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
va dan » ca dan, va dao, va dau
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: thu ((sach doi) OR (sach moi)) nang o hoi. hieu van cam xuc ((ban hanh) or (va dan)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach doi) OR (sach moi)) nang o hoi. hieu van cam xuc ((ban hanh) OR (va dan)) vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach doi) OR (sach moi)) nang o hoi. hieu van cam xuc ((ban hanh) or (va dan)) vai cua tre*".