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