Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cua viet » ca viet, hoa viet, cua vat
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
su sai » su tai, su hai, su dai
sai ky » sac ky
ma hoi » xa hoi, ma hoa, me hoi
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: su sai ky nang ((ma hoi) or (mai hoi)). hieu ve cac duc van hanh vi ((cua viet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky nang ((ma hoi) OR (mai hoi)). hieu ve cac duc van hanh vi ((cua viet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sai ky nang ((ma hoi) or (mai hoi)). hieu ve cac duc van hanh vi ((cua viet) or (va triet))*.