Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh hai » thanh phan, thanh hoa, thanh san
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
dua ban » dia ban, cua ban, qua ban
hai cua » thai cua, dai cua, hoi cua
su sach » so sach, vu sach
ky tang » ky nang, ky dang, kho tang
dao dua » dao duc, dao duy, dai dua
su sac » su cac, su xac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) or (su sach)) ky tang ((ma hoa) or (xa hoi)). hieu van dao dua ban thanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su sach)) ky tang ((ma hoa) OR (xa hoi)). hieu van dao dua ban thanh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((su sac) or (su sach)) ky tang ((ma hoa) or (xa hoi)). hieu van dao dua ban thanh hai cua tre*.