Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
danh vai » danh sai, danh va, doanh van
vai cua » dai cua, hai cua, lai cua
va danh » va dinh, va dan, va hanh
cam thu » nam thu, cac thu, ca thu
so sach » so sanh, bo sach, co sach
hieu ve » hieu va
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
sach v » sach va, sach y, sach 2
thu va » thuc va, thue va, tu va
v nang » va nang, vu nang, van nang

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 v nang ((mai hoi) or (lai hoi)). ((hieu ve) OR (hieu van)) cam thu va danh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v nang ((mai hoi) OR (lai hoi)). ((hieu ve) OR (hieu van)) cam thu va danh vai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v nang ((mai hoi) or (lai hoi)). ((hieu ve) OR (hieu van)) cam thu va danh vai cua viet".
• Adding a wildcard symbol may retrieve word variants: so sach v nang ((mai hoi) or (lai hoi)). ((hieu ve) OR (hieu van)) cam thu va danh vai cua viet*.