Die Bau- und Kunstdenkmäler von Westfalen: Band 12: Kreis Siegen. Münster i.W.: Schöningh, 1903
<a href="https://en.wikipedia.org/wiki/de:Albert_Ludorff" class="extiw" title="w:de:Albert Ludorff">Albert Ludorff</a>
1903
<a rel="nofollow" class="external text" href="https://books.google.com/books?id=fYYEAAAAYAAJ">Google Books-USA</a><a href="https://en.wikisource.org/wiki/Wikisource:GBSUS" class="extiw" title="s:Wikisource:GBSUS">*</a>