Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
mai hoi » mai khoi, dai hoi, mai doi
lai hoi » dai hoi, lai hoa, lai roi
hieu ve » hieu va, hieu van
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
vi cua » vai cua, di cua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang ((mai hoi) OR (lai hoi)). hieu ve cac ((duc tan) OR (luc canh)) hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky nang ((mai hoi) OR (lai hoi)). hieu ve cac ((duc tan) or (luc canh)) hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: te sac ky nang ((mai hoi) OR (lai hoi)). hieu ve cac ((duc tan) or (luc canh)) hanh vi cua viet*.