@book{100057,
	author = {David, Charles W.},
	title = {Robert Curthose, Duke of Normandy},
	publisher = {Project Gutenberg,},
	year = {2019},
	series = {Harvard Historical Studies, volume XXV},
	address = {Salt Lake City, UT :},
	note = {Release date is 2019-04-08},
	url = {https://www.gutenberg.org/ebooks/59231}
}