Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh de » hanh de, thanh ve, thanh do
thuc ban » thuoc ban, thuc dan, thu ban
cua tre » cua te, cuu tre, cua triet
mai hoi » mai khoi, dai hoi, lai hoi
de cua » le cua, te cua, dieu cua
tu cao » cu cao, tu cac, vu cao
he nam » ha nam, nghe nam
ma hoi » xa hoi, ma hoa, me hoi
le nam » ly nam, le na, te nam

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: tu cao ky nang ((ma hoi) OR (mai hoi)). hieu ((le nam) OR (he nam)) thuc ban thanh de cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cao ky nang ((ma hoi) or (mai hoi)). hieu ((le nam) OR (he nam)) thuc ban thanh de cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu cao ky nang ((ma hoi) or (mai hoi)). hieu ((le nam) OR (he nam)) thuc ban thanh de cua tre*.