<div class="fn value">
<a href="https://en.wikisource.org/wiki/de:K._F._Vierordt" class="extiw" title="s:de:K. F. Vierordt">K. F. Vierordt</a></div>
books.google.com, <a rel="nofollow" class="external text" href="https://books.google.com/books?id=LiUBAAAAYAAJ">Google Books</a>