<bdi><a href="https://en.wikipedia.org/wiki/en:Otto_Lilienthal" class="extiw" title="w:en:Otto Lilienthal"><span title="German aviation pioneer (1848-1896)">Otto Lilienthal</span></a>
</bdi>
<a rel="nofollow" class="external free" href="https://archive.org/details/VogelflugalsGru00Lili">https://archive.org/details/VogelflugalsGru00Lili</a>