Perhaps you should try some spelling variations:
ban thanh » ban hang
thue nang » thien nang, thuat nang, thi nang
sach thue » sach thu, sach thieu, sach tham
ban hanh » ban hang
su sach » so sach, vu sach
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va chat » van chat, va phat, cao chat
va cham » va tham
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thue nang o hoc. hieu ((va cham) OR (va chat)) duc ((ban thanh) or (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thue nang o hoc. hieu ((va cham) OR (va chat)) duc ((ban thanh) OR (ban hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thue nang o hoc. hieu ((va cham) OR (va chat)) duc ((ban thanh) or (ban hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach thue nang o hoc. hieu ((va cham) OR (va chat)) duc ((ban thanh) or (ban hanh)) vai cua tre*.