^Landauer, Carl; Landauer, Hilde Stein; Valkenier, Elizabeth Kridl (1979) [1959]. "The Three Anticapitalistic Movements". European Socialism: A History of Ideas and Movements from the Industrial Revolution to Hitler's Seizure of Power. University of California Press. pp. 59, 63. "In France, post-Utopian socialism begins with Peter Joseph Proudhon. [...] [Proudhon] was the most profound thinker among pre-Marxian socialists."
^Eatwell, Roger; Wright, Anthony (1999). Contemporary Political Ideologies (2nd ed.). London: Continuum. p. 82. ISBN9781855676053.
^Newman, Michael (2005). Socialism: A Very Short Introduction. Oxford University Press. p. 15. ISBN9780192804310.
^Docherty, James C.; Lamb, Peter, eds. (2006). Historical Dictionary of Socialism. Historical Dictionaries of Religions, Philosophies, and Movements. 73 (2nd ed.). Lanham, Maryland: The Scarecrow Press. p. 284. ISBN9780810855601. See also Lamb, Peter (2015). Historical Dictionary of Socialism (3rd ed.). Lanham: Rowman & Littlefield. pp. 36, 57, 161, 263, 385. ISBN9781442258273.
^Merriman, John M. (2009). How a Bombing in Fin-de-Siècle Paris Ignited the Age of Modern Terror. New Haven: Yale University Press. p. 42. ISBN9780300217933.
^Leier, Mark (2006). Bakunin: The Creative Passion. New York: Seven Stories Press. p. 211. ISBN9781583228944.
^Guérin, Daniel (1989) [1970]. Anarchism: From Theory to Practice. New York: Monthly Review Press. ISBN9780853451754.