Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » vu sach
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
cac toc » cac toi, cac nuoc, cac thoi
cac tuc » cac tu, cac tac, cac nuoc
so sach » so sanh, bo sach, co sach
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca 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) OR (so sach)) ky nang x hoi. hieu van ((cac tuc) OR (cac toc)) va hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) ky nang x hoi. hieu van ((cac tuc) or (cac toc)) va hanh va cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) ky nang x hoi. hieu van ((cac tuc) or (cac toc)) va hanh va cua tre*.