D'<a href="https://lb.wikipedia.org/wiki/Adolf-Emil-H%C3%BCtte" class="extiw" title="lb:Adolf-Emil-Hütte">Adolf-Emil-Hütte</a>.
Unknown author<span style="display: none;">Unknown author</span>
<a rel="nofollow" class="external text" href="https://www.industrie.lu/UsineBelvalHFx.html">Collection industrie.lu</a> (Gelsenkirchener Bergwerks-Aktien-Gesellschaft, Abteilung Aachener Hütten-Verein)