@book{128007,
	author = {Wittgenstein, Ludwig, and Pears, David,},
	title = {Tractatus logico-philosophicus /},
	publisher = {Routledge,},
	year = {c2001.},
	address = {London :},
	note = {Originally published: 1975.},
	url = {http://www.loc.gov/catdir/enhancements/fy0650/2001041223-d.html}
}