Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
va tuyen » va truyen, tac tuyen, ke tuyen
mai hoi » mai khoi, dai hoi, mai doi
lai hoi » dai hoi, lai hoa, lai roi
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
cac duc » cac du, cao duc, cac dac
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua te » cua tu
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang ((mai hoi) or (lai hoi)). hieu ve cac duc va danh vi ((cua te) or (va tuyen))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang ((mai hoi) OR (lai hoi)). hieu ve cac duc va danh vi ((cua te) OR (va tuyen)).
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang ((mai hoi) or (lai hoi)). hieu ve cac duc va danh vi ((cua te) or (va tuyen))*.