Show a link over links to epub files

JavaScript
1

I’d like to provide an automatic link over my links to epub files (a link to a page about e-readers).

  1. With css I can add a content, like this:
li a[href $='.epub']:hover:after {content: " to read these files you can use an e-reader";
  text-decoration: none; color: gray; font-size: 80%;}

with an html like this:

<li><b>Delitto e castigo</b>: <a href="dostoevskij/Delitto e castigo.epub"></a>.</li> 
<li><b>I Demoni</b>: <a href="dostoevskij/I Demoni.epub"></a>.</li>

And it works, but without any link.

  1. So, I found that with this jquery code
$(function(){
    $('#HPV').hover(function(e){
       $(this).append('<a href="google.com">click me</a>');;
    },function(){
       $(this).find('a').remove();;
    });
});

I can add link for all html with Id = HPV.
But what code could I use to have a linkable text for all links to epub files?
I guess that the string to modify is this: $('#HPV'), but how?