Project Gutenberg 2010-04-24 Public domain in the USA. 489 Moulton, Forest Ray 1872 1952 Moulton, F. R. (Forest Ray) An Introduction to Astronomy en Astronomy QB Text Astronomy 13901425 2010-04-24T18:57:15 application/pdf 9111 2025-10-13T07:08:56.461240 application/rdf+xml 1370135 2021-06-11T17:20:24 application/prs.tex 11769 2025-10-13T07:08:56.384228 image/jpeg 2814 2025-10-13T07:08:56.132247 image/jpeg 13136093 2010-04-24T18:57:17 application/octet-stream application/zip 11990135 2021-06-11T17:20:24 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