Project Gutenberg 2012-03-09 Public domain in the USA. 158 De Morgan, Augustus 1806 1871 Morgan, Augustus de On the study and difficulties of mathematics en Algebra Geometry Mathematics -- Study and teaching QA Text Mathematics 1444917 2013-02-17T16:52:41 application/pdf 10244 2025-07-16T03:55:50.979789 application/rdf+xml 554309 2021-06-11T17:21:28 application/prs.tex 15564 2025-07-16T03:55:50.915791 image/jpeg 3550 2025-07-16T03:55:50.673787 image/jpeg 1199354 2013-02-17T16:52:42 application/octet-stream application/zip 487752 2021-06-11T17:21:28 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 en.wikipedia