Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
cac thuc » cach thuc, cac thu, can thuc
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
su sach » so sach, vu sach
so sanh » do sanh
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
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) OR (so sanh)) v nang x hoi. ((hieu van) OR (thien van)) cac thuc va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sanh)) v nang x hoi. ((hieu van) OR (thien van)) cac thuc va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sanh)) v nang x hoi. ((hieu van) OR (thien van)) cac thuc va hanh vi cua tre*.