Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
ca chua » ca cua, sua chua
va chua » vua chua, va chu, a chua
xuc ban » duc ban, cuc ban, quoc ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
van bac » van ban, van bao, van hac

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 sach ky ((nang xa) OR (nang ma)) hoi. hieu van bac xuc ban thanh ((va chua) OR (ca chua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) or (nang ma)) hoi. hieu van bac xuc ban thanh ((va chua) OR (ca chua)) triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) or (nang ma)) hoi. hieu van bac xuc ban thanh ((va chua) OR (ca chua)) triet*.