Perhaps you should try some spelling variations:
ban thanh » ban hang
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
hoa cua » hoa chat, hoa xuat
qua am » quan am, qua ap, cua am
am hoc » ad hoc
cua tu » cua tuc, cua su, cua cu

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 nang ((van hoa) or (van hoc)). hieu qua am hoc ((ban thanh) or (ban hanh)) hoa cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((van hoa) OR (van hoc)). hieu qua am hoc ((ban thanh) OR (ban hanh)) hoa cua tu.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((van hoa) or (van hoc)). hieu qua am hoc ((ban thanh) or (ban hanh)) hoa cua tu*.