"Classroom Without Walls". Explorations Magazine, Volume 7, 1957; reprinted in "Explorations in Communication" edited by E. Carpenter and M. McLuhan, 1960, and in "McLuhan: Hot and Cool" edited by Gerald Emanuel Stearn, 1967.
Marshall McLuhan, W. Terrence Gordon, Elena Lamberti, Dominique Scheffel-Dunand (2011). “The Gutenberg Galaxy: The Making of Typographic Man”, p.208, University of Toronto Press
Marshall McLuhan, W. Terrence Gordon, Elena Lamberti, Dominique Scheffel-Dunand (2011). “The Gutenberg Galaxy: The Making of Typographic Man”, p.183, University of Toronto Press
Marshall McLuhan, Bruce R. Powers (1989). “The global village: transformations in world life and media in the 21st century”, Oxford University Press, USA
Marshall McLuhan, W. Terrence Gordon, Elena Lamberti, Dominique Scheffel-Dunand (2011). “The Gutenberg Galaxy: The Making of Typographic Man”, p.330, University of Toronto Press