@book{108104,
	author = {Spencer, Herbert,},
	title = {The Principles of Biology, Volume 2 (of 2)},
	publisher = {Project Gutenberg,},
	year = {2022},
	address = {Salt Lake City, UT :},
	note = {Release date is 2022-01-30},
	url = {https://archive.org/details/principlesofbiol02speniala/page/n5/mode/2up}
}