Perhaps you should try some spelling variations:
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
doi cua » dai cua, hoi cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
mang xa » mang may, dang xay, mang cua
va nay » va ngay, va cay
cua te » cua tu

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 ((mang xa) OR (lang xa)) hoi. hieu va nay xuc ((ban hanh) OR (ban hang)) doi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((mang xa) or (lang xa)) hoi. hieu va nay xuc ((ban hanh) OR (ban hang)) doi cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((mang xa) or (lang xa)) hoi. hieu va nay xuc ((ban hanh) OR (ban hang)) doi cua te*.