@book{66158,
	author = {Lie, Sophus,},
	title = {Über Integralinvarianten und Differentialgleichungen},
	publisher = {Project Gutenberg,},
	year = {2008},
	address = {Salt Lake City, UT :},
	note = {Release date is 2008-04-24},
	url = {https://www.gutenberg.org/ebooks/25157}
}