@book{22611,
	author = {Groen, J.J.,},
	title = {Ethica en Ethologie :},
	publisher = {Brill,},
	year = {1972.},
	series = {European History and Culture - Book Archive pre-2000},
	address = {Leiden ;},
	url = {http://dx.doi.org/10.1163/9789004622203}
}