Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
toc sach » hoc sach, doc sach, thuoc sach
sang tay » sang tao, sang tai, sang tac
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, va tinh, le thanh
ky sang » ky nang, ky dang, ky tang
tay hoi » tay ho, tao hoi, tay thai
hieu ve » hieu va
lai cua » dai cua, hai cua, lai chau
sach ky » sac ky, sach y, sach ty
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky sang tay hoi. ((hieu ve) OR (hieu van)) pham duc ((va thanh) or (ban thanh)) lai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky sang tay hoi. ((hieu ve) OR (hieu van)) pham duc ((va thanh) OR (ban thanh)) lai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky sang tay hoi. ((hieu ve) OR (hieu van)) pham duc ((va thanh) or (ban thanh)) lai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach ky sang tay hoi. ((hieu ve) OR (hieu van)) pham duc ((va thanh) or (ban thanh)) lai cua te*.