Removing underline from hyperlinks heading 3 only

Hi there, how do I remove the underline from hyperlinks on my heading 3 only?

/* Remove underline from links */
a {
   border: none !important;
   }

removes all,

/* Remove underline from links */
 heading a {
   border: none !important;
   }

does nothing for me.

heading 3 sound like <h3> for me? could you show your site url so we can provide the exact snippet for this?