Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
cao hoi » cau hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
cac dua » cach dua, cac qua, cac du
san cua » sang cua, ban cua, dan cua
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc, co loi

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty nang ((cao hoi) or (co hoi)). hieu va cac dua ((ban thanh) or (ban hanh)) san cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty nang ((cao hoi) OR (co hoi)). hieu va cac dua ((ban thanh) OR (ban hanh)) san cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach ty nang ((cao hoi) or (co hoi)). hieu va cac dua ((ban thanh) or (ban hanh)) san cua tre*.