Perhaps you should try some spelling variations:
ban thanh » ban hanh
cham cua » chat cua, cham cuu, ham cua
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
dai moi » doi moi, dai hoi
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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 y nang ((mai hoi) or (dai moi)). hieu ve cham cua ((ban thanh) OR (ban hang)) hoc cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((mai hoi) OR (dai moi)). hieu ve cham cua ((ban thanh) OR (ban hang)) hoc cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((mai hoi) or (dai moi)). hieu ve cham cua ((ban thanh) OR (ban hang)) hoc cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((mai hoi) or (dai moi)). hieu ve cham cua ((ban thanh) OR (ban hang)) hoc cua tre*.