Mark Kac, Gian-Carlo Rota, Jacob T. Schwartz (2009). “Discrete Thoughts: Essays on Mathematics, Science and Philosophy”, p.263, Springer Science & Business Media

Mark Kac, Gian-Carlo Rota, Jacob T. Schwartz (2009). “Discrete Thoughts: Essays on Mathematics, Science and Philosophy”, p.62, Springer Science & Business Media

Mark Kac, Gian-Carlo Rota, Jacob T. Schwartz (2009). “Discrete Thoughts: Essays on Mathematics, Science and Philosophy”, p.4, Springer Science & Business Media