http://book.klll.cc/ebooks/author/58432.opds 2025-11-18T02:37:11Z Books by Motte, Andrew Free eBooks since 1971. Project Gutenberg https://book.klll.cc webmaster@gutenberg.org https://book.klll.cc/gutenberg/favicon.ico 25 1 2025-11-18T02:37:11Z https://book.klll.cc/ebooks/76404.opds Newton's Principia : The mathematical principles of natural philosophy Isaac Newton