Antonio Favaro, 1890–1909 (reprint: Florence: Barbèra, 1968) are cited by the title Opere, followed by the number of the volume and the page. For instance, Opere, XIX, 342 means volume XIX, page 342.
The documents of the trial of Galileo are also found in Sergio Pagano (ed.), I documenti del processo di Galileo Galilei (Vatican City: Pontifical Academy of Sciences, 1984), which is quoted as Documenti, followed by the page number.
p. 9: Decrees of the Ecumenical Councils, edited by Norman P. Tanner S.J., Volume Two: Trent to Vatican. London and Washington: Sheed & Ward and Georgetown University Press, 1990 II, 664.
p.22: “Here we have a powerful and elegant argument”: final part of Sidereus Nuncius, in Opere, III, 95.
p.23: “The Maker of the stars Himself”: dedication of Sidereus Nuncius, in Opere, III 8 56.
p.25: “Mother of Love”: letter from Galileo to Giulano de Medici, January 1611, in Opere XI, 12.
p.27: “And the author runneth”: letter from Henry Wotton to the Earl of Salusbury, 13 March 1610, in the Life and Letters of Sir Henry Wotton edited by Logon Pearsall Smith, Oxford, 1907, I, pp. 486–48.
p.29: “Our beloved Mathematician and Philosopher”: letter from Grand Duke Cosimo II to Giovanni Niccolini, 27 February 1611, in Opere, XI, 60.
p.29: “In order to put an end, once and for all, to malignant rumours”: letter from Galileo to Belisario Vinta, 19 March 1611, in Opere, XI, 71.
p.31: “I arrived in good health on Holy Tuesday”: letter from Galileo to Belisario Vinta, 1 April 1611, in Opere, XI, 79.