@book{39309,
	author = {Osterbrock, Donald E. and ebrary, Inc.},
	title = {Yerkes Observatory, 1892-1950},
	publisher = {University of Chicago Press,},
	year = {1997.},
	address = {Chicago :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10230065}
}