@book{69142,
	author = {Newton, Isaac,},
	title = {Philosophiae Naturalis Principia Mathematica},
	publisher = {Project Gutenberg,},
	year = {2009},
	address = {Salt Lake City, UT :},
	note = {Wikipedia page about this book: https://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica Wikipedia page about this book: https://sco.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica},
	url = {https://www.gutenberg.org/ebooks/28233}
}