Perhaps you should try some spelling variations:
thien van » thi van
hieu van » hieu va, lieu va, hieu ve
va hanh » van hanh, va thanh, va danh
cac tac » cac toc, cac bac, cac dac
su sach » vu sach
cua tre » cua te, cuu tre, cua triet
so sach » so sanh, bo sach, co sach
v nang » va nang, vu nang, van nang
tac va » tac da, tac xa, tuc va
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.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) or (so sach)) v nang x hoi. ((hieu van) or (thien van)) cac tac va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) v nang x hoi. ((hieu van) OR (thien van)) cac tac va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) v nang x hoi. ((hieu van) or (thien van)) cac tac va hanh vi cua tre*.