Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
va hanh » van hanh, va danh, ban hanh
lai cua » dai cua, hai cua, lai chau
cac toc » cac toi, cac nuoc, cac thoi
van cac » van hac, van cau, van bac
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
su cac » tu cac, su cao, su can

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