Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
toc xa » tuc xa, toc ta, tac xa
hoc xa » hoc ma
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.

• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. hieu van cac ((toc xa) OR (hoc xa)) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu van cac ((toc xa) OR (hoc xa)) hanh vi cua tre*.