Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
mua ban » cua ban, qua ban
nam mua » nam cua, nam qua, nam xua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may

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: su sach y ((nang ma) OR (tang ma)) hoi. ((hieu ve) OR (hieu va)) nam mua ban thanh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang ma) OR (tang ma)) hoi. ((hieu ve) or (hieu va)) nam mua ban thanh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach y ((nang ma) OR (tang ma)) hoi. ((hieu ve) or (hieu va)) nam mua ban thanh vai cua tre*.