@book{100459,
	author = {Baker, Daniel W. and Pickering, Edward C.},
	title = {History of the Harvard College Observatory During the Period 1840-1890},
	publisher = {Project Gutenberg,},
	year = {2019},
	address = {Salt Lake City, UT :},
	note = {Release date is 2019-05-30},
	url = {https://www.gutenberg.org/ebooks/59633}
}