http://book.klll.cc/ebooks/author/51653.opds 2025-09-19T10:24:52Z Books by Langhoff, F. (sorted by popularity) Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-09-19T10:24:52Z https://book.klll.cc/ebooks/61873.opds Warum und Weil. Physikalischer Teil. (German) Otto Ule