http://book.klll.cc/ebooks/author/57047.opds?sort_order=downloads 2025-11-16T18:00:04Z Books by Burckhardt, Rudolf Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-16T18:00:04Z https://de.wikipedia.org/wiki/Rudolf_Burckhardt_(Zoologe) See also: de.wikipedia 2025-11-16T18:00:04Z https://book.klll.cc/ebooks/73374.opds Geschichte der Zoologie (German) Rudolf Burckhardt