Perhaps you should try some spelling variations:
ban thanh » ban hang
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
dang xay » dang van, van xay
sach ky » sac ky, sach y, sach ty
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
dang xa » lang xa, dang ha, dang va
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((dang xa) OR (dang xay)) hoi. hieu van cam duc ((ban thanh) or (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((dang xa) OR (dang xay)) hoi. hieu van cam duc ((ban thanh) OR (ban hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((dang xa) OR (dang xay)) hoi. hieu van cam duc ((ban thanh) or (ban hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((dang xa) OR (dang xay)) hoi. hieu van cam duc ((ban thanh) or (ban hanh)) vai cua tre*.