Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
cach tu » cach thuc
van cac » van hac, van cau, van bac
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
cac tu » cac thu, cac du, tac tu
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, x ho

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 ky) OR (cach tu)) nang x hoi. hieu van cac tu va hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (cach tu)) nang x hoi. hieu van cac tu va hanh vi cua tre*.