G. Spencer-Brown: Frases en inglés
Fuente: Laws of Form, (1969), p. 1, cited in Niklas Luhmann, Risk: A Sociological Theory, Walter de Gruyter, 1993 p. 223.
Fuente: Laws of Form, (1969), p. 104-05; as cited in: David Phillip Barndollar (2004) The Poetics of Complexity and the Modern Long Poem https://www.lib.utexas.edu/etd/d/2004/barndollardp50540/barndollardp50540.pdf, The University of Texas at Austin, p. 12-13.