Perhaps you should try some spelling variations:
thanh dai » thanh hai, thanh tai, thanh dat
ban thanh » ban hanh, ban hang
kho tang » cao tang
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, ky trong
ma hoi » mai hoi, xa hoi, me hoi
du ban » dua ban, duc ban, du bao

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: te sach ((ky tang) OR (kho tang)) ((ma hoi) OR (ma hoa)). hieu van cac du ban thanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky tang) OR (kho tang)) ((ma hoi) or (ma hoa)). hieu van cac du ban thanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky tang) OR (kho tang)) ((ma hoi) or (ma hoa)). hieu van cac du ban thanh dai cua tre*.