Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
sang tao » hang tai
tai cua » thai cua, tri cua, dai cua
duc ban » duc tan, duc van, dua ban
dau duc » dao duc, dang duc, dau nuoc
van dau » van dao, phan dau
tao hoi » tao khoi, tao boi, tay hoi
ky sang » ky nang, ky dang, ky tang

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) OR (toc sach)) ky sang tao hoi. hieu van dau duc ban thanh ((tai cua) OR (tai cuc)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky sang tao hoi. hieu van dau duc ban thanh ((tai cua) or (tai cuc)) tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky sang tao hoi. hieu van dau duc ban thanh ((tai cua) or (tai cuc)) tre*.