Perhaps you should try some spelling variations:
ban thanh » ban hang
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
cam dua » ca dua, cay dua, chay dua
hai cuc » tai cuc, hai cua, thai cua
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
ty nang » ky nang, ty xang, ty hang
cuc tre » duc tre, cua tre, cuu tre
ve cam » ve cham, ve cac, va cam

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 ty nang ((mai hoi) or (lai hoi)). hieu ve cam dua ((ban thanh) OR (ban hanh)) hai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ty nang ((mai hoi) OR (lai hoi)). hieu ve cam dua ((ban thanh) OR (ban hanh)) hai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang ((mai hoi) or (lai hoi)). hieu ve cam dua ((ban thanh) OR (ban hanh)) hai cuc tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang ((mai hoi) or (lai hoi)). hieu ve cam dua ((ban thanh) OR (ban hanh)) hai cuc tre*.