Isaac, Richard E. (1995). The Pleasures of Probability. Springer. hlm. 48–50. ISBN 0-387-94415-X. Isaac generalizes this argument immediately to variable text and alphabet size; the common main conclusion is on p.50.
Lucas, J. R. (1979). "Wilberforce and Huxley: A Legendary Encounter". The Historical Journal. 22 (2): 313–330.Parameter |month= yang tidak diketahui akan diabaikan (bantuan) Also available at [1]Diarsipkan 2011-04-10 di Wayback Machine., Retrieved on 2007-03-07
Lucas, J. R. (1979). "Wilberforce and Huxley: A Legendary Encounter". The Historical Journal. 22 (2): 313–330.Parameter |month= yang tidak diketahui akan diabaikan (bantuan) Also available at [1]Diarsipkan 2011-04-10 di Wayback Machine., Retrieved on 2007-03-07