@book{28820,
	author = {Frege, Gottlob, and Bynum, Terrell Ward,},
	title = {Conceptual notation, and related articles /},
	publisher = {Clarendon Press,},
	year = {1972.},
	address = {Oxford :},
	note = {Include index},
	url = {http://www.loc.gov/catdir/enhancements/fy0606/73155636-d.html}
}