@book{96818,
	author = {Gray, Asa, and Gray, Jane Loring,},
	title = {Letters of Asa Gray; Vol. 2},
	publisher = {Project Gutenberg,},
	year = {2017},
	address = {Salt Lake City, UT :},
	note = {Release date is 2017-11-17},
	url = {https://www.gutenberg.org/ebooks/55987}
}