Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
chat soc » cham soc, chat hoc, chat doc
soc van » hoc van, oc van, sac van
ve chat » va chat, van chat
hieu ve » hieu va, hieu van
mai hoi » mai khoi, dai hoi, lai hoi
ky sang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
me hoi » le hoi
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky sang ((me hoi) or (mai hoi)). hieu ve chat soc van hanh ((ly cua) or (le cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky sang ((me hoi) OR (mai hoi)). hieu ve chat soc van hanh ((ly cua) OR (le cua)) tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky sang ((me hoi) or (mai hoi)). hieu ve chat soc van hanh ((ly cua) or (le cua)) tre*.