Perhaps you should try some spelling variations:
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
hieu va » lieu va, hieu qua
cam dua » ca dua, cay dua, chay dua
dua ban » dia ban, cua ban, qua ban
bai cua » ban cua, hai cua, lai cua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang cao hoi. hieu va cam dua ban hang ((((bai cua) or (bai ca))) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. hieu va cam dua ban hang ((((bai cua) OR (bai ca))) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. hieu va cam dua ban hang ((((bai cua) or (bai ca))) or (dai cua)) tre*.