@book{66963,
	author = {Gotthelf, Allan,},
	title = {Concepts and their role in knowledge :},
	publisher = {University of Pittsburgh Press,},
	year = {2013.},
	series = {Ayn Rand Society Philosophical Studies},
	address = {Pittsburgh, Pennsylvania :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10904624}
}