Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
sach thu » sach thue, sach thieu, sach tham
cao duc » dao duc, cao suc, tao duoc
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, xach tay
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc

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

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