Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nuoc ban » nuoc san, quoc ban, buoc ban
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, mai doi
lai hoi » dai hoi, lai hoa, lai roi
y nang » ky nang, ly nang, v nang
vi cua » di cua

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 (lai hoi)). hieu va cac nuoc ban thanh ((vi cua) OR (vai cua)) duc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((mai hoi) OR (lai hoi)). hieu va cac nuoc ban thanh ((vi cua) OR (vai cua)) duc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((mai hoi) or (lai hoi)). hieu va cac nuoc ban thanh ((vi cua) OR (vai cua)) duc".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((mai hoi) or (lai hoi)). hieu va cac nuoc ban thanh ((vi cua) OR (vai cua)) duc*.