Marx text:
Karl Marx, Preface to the Contribution to the Critique of Political Economy (1959)
-
in Later Political Writings, trans. Terrell Carver (Cambridge: Cambridge University Press, 1996), pp. 158-162.
-
in The Marx-Engels Collected Works, Vol. 28 (London: Lawrence and Wishart, 2014)
-
online at marxists.org/archive/marx/works/1859/critique-pol-economy/preface.htm
Karl Marx, Capital, Vol. 1
-
from trans. Ben Fowkes (New York: Penguin Classics, 1992)
-
in The Marx-Engels Collected Works, Vol. 35 (London: Lawrence and Wishart, 2014)
-
online at marxists.org/archive/marx/works/1867-c1