Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
vu sach » vu bach, su sach, vu khach
vai cua » dai cua, hai cua, lai cua
cao duc » dao duc, cao suc, tao duoc
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
cua tre » cua te, cuu tre, cua triet

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((nang ma) OR (tang ma)) 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 ((nang ma) OR (tang ma)) hoi. hieu va ((cao duc) or (giao duc)) ban thanh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((nang ma) OR (tang ma)) hoi. hieu va ((cao duc) or (giao duc)) ban thanh vai cua tre*.