http://book.klll.cc/ebooks/author/55928.opds?sort_order=release_date 2025-11-17T11:05:53Z Books by Freundlich, Erwin Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-17T11:05:53Z https://de.wikipedia.org/wiki/Erwin_Freundlich See also: de.wikipedia 2025-11-17T11:05:53Z https://en.wikipedia.org/wiki/Erwin_Finlay-Freundlich See also: en.wikipedia 2025-11-17T11:05:53Z https://book.klll.cc/ebooks/70793.opds The foundations of Einstein's theory of gravitation Erwin Freundlich