Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cac toc » cac toi, cac nuoc, cac thoi
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
cac tu » cac thu, cach tu, cac du
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 y nang x hoi. ((hieu van) OR (hieu va)) ((cac tu) OR (cac toc)) va danh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang x hoi. ((hieu van) OR (hieu va)) ((cac tu) or (cac toc)) va danh va cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. ((hieu van) OR (hieu va)) ((cac tu) or (cac toc)) va danh va cua tre*.