↑ Index Librorum Prohibitorum, 1559, Regula Quarta ("Rule 4")
↑ Charles B. Schmitt, et al. The Cambridge History of Renaissance Philosophy (Cambridge University Press, 1991), "Printing and censorship after 1550", p.45ff.
↑ Index of Prohibited Books, Revised, Vatican Polyglot Press, 190
↑ Paula Findlen, "A Hungry Mind: Giordano Bruno, Philosopher and Heretic", The Nation, September 10, 2008. "Campo de' Fiori was festooned with flags bearing Masonic symbols. Fiery speeches were made by politicians, scholars and atheists about the importance of commemorating Bruno as one of the most original and oppressed freethinkers of his age." Accessed on 19 September 2008
↑ Paul Henry Michel. The Cosmology of Giordano Bruno. R.E.W. Maddison, translator. Cornell University Press 1962
