Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thu sach » thuat sach, thuoc sach, thu hoach
hanh vai » hanh vi, hanh va, hanh tai
tu sach » su sach, te sach, tu cach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cac lop » cac hop, cac loai
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
tay oi » tay hoi, tay doi, tay loi
lop va » lap va, hop va, nop va
ky va » ly va, ke va, my va
tay o » tay co

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: ((tu sach) OR (thu sach)) ky va ((tay oi) OR (tay o)). hieu van cac lop va hanh vai cua tre~.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky va ((tay oi) or (tay o)). hieu van cac lop va hanh vai cua tre*.