Walker, Ignacio (1990). "Socialismo y Democracía"(PDF). Cieplan. p. 230. Archived from the original(PDF) on 24 September 2015. Retrieved 11 November 2014.
Walker, Ignacio (1990). "Socialismo y Democracía"(PDF). Cieplan. p. 230. Archived from the original(PDF) on 24 September 2015. Retrieved 11 November 2014.