http://book.klll.cc/ebooks/author/47930.opds?sort_order=release_date 2025-11-18T14:41:09Z Books by Lilienthal, Otto Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-18T14:41:09Z https://en.wikipedia.org/wiki/Otto_Lilienthal See also: en.wikipedia 2025-11-18T14:41:09Z https://book.klll.cc/ebooks/54565.opds Der Vogelflug als Grundlage der Fliegekunst (German) Otto Lilienthal