Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, va tinh, le thanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
nam xuc » cam xuc, nam xua, nam thuc
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
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 ky nang x hoi. ((hieu van) or (hieu va)) nam xuc ((va thanh) OR (ban thanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. ((hieu van) OR (hieu va)) nam xuc ((va thanh) OR (ban thanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang x hoi. ((hieu van) or (hieu va)) nam xuc ((va thanh) OR (ban thanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. ((hieu van) or (hieu va)) nam xuc ((va thanh) OR (ban thanh)) vai cua tre*.