@book{90449,
	author = {Wittgenstein, Ludwig},
	title = {Tractatus logico-philosophicus},
	publisher = {Routledge and Kegan Paul},
	year = {[1972,c1975]},
	series = {International library of philosophy and scientific method},
	address = {London},
	edition = {2. ed.},
	note = {English and German.}
}