<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="//apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<p>Subtitles icon: <span class="glyphicon glyphicon-subtitles"></span></p>
<p>Subtitles icon as a link:
<span class="glyphicon glyphicon-subtitles"></span>
<p>Subtitles icon on a button:
<button type="button" class="btn btn-default btn-sm">
<span class="glyphicon glyphicon-subtitles"></span> Subtitles
<p>Subtitles icon on a styled link button:
<a href="#" class="btn btn-info btn-lg">
<span class="glyphicon glyphicon-subtitles"></span> Subtitles
<script src="//apps.bdimg.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="//apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>