{% if page.previous_page or page.next_page %}
  <h3>Related Topics</h3>
  <ul>
    {% if page.previous_page %}
      <li>Previous: <a href="{{page.previous_page.url|url}}" title="previous chapter">
        {{page.previous_page.title}}
      </a></li>
    {% endif %}
    {% if page.next_page %}
      <li>Next: <a href="{{page.next_page.url|url}}" title="next chapter">
        {{page.next_page.title}}
      </a></li>
    {% endif %}
  </ul>
{% endif %}