Über die spezielle und die allgemeine Relativitätstheorie, by Albert 77850 Einstein [Subtitle: (Gemeinverständlich)] [Author: Albert Einstein] [Editor: Karl Scheel] [Language: German] [Link: https://www.gutenberg.org/ebooks/77850] note: link will be active within two hours of posting. Thanks to Jana Srna and the Online Distributed Proofreading Team at https://www.pgdp.net Regards, Robert