Project Gutenberg 2009-08-26 Public domain in the USA. 67 Frischauf, Johannes 1837 1924 Elemente der Absoluten Geometrie de Geometry, Non-Euclidean QA Text Mathematics DE Sachbuch 948049 2009-08-26T07:59:53 application/pdf 9916 2025-07-12T09:17:15.126085 application/rdf+xml 367599 2009-08-26T07:59:53 application/prs.tex 14416 2025-07-12T09:17:15.060081 image/jpeg 3604 2025-07-12T09:17:14.821097 image/jpeg 790063 2009-08-26T07:59:53 application/octet-stream application/zip 500040 2009-08-26T07:59:53 application/octet-stream application/zip Archives containing the RDF files for *all* our books can be downloaded at https://book.klll.cc/wiki/Gutenberg:Feeds#The_Complete_Project_Gutenberg_Catalog de.wikipedia