Perhaps you should try some spelling variations:
tinh vai » tinh va, tinh hai, tinh bai
su sach » so sach
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, vu khach
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho
bo va » bao va, do va, co va
so va » so van, so vat, su va

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) OR (vu sach)) ky nang x hoi. hieu ve cac ((bo va) OR (so va)) tinh vai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (vu sach)) ky nang x hoi. hieu ve cac ((bo va) OR (so va)) tinh vai cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ky nang x hoi. hieu ve cac ((bo va) OR (so va)) tinh vai cua tre*.