1. Due Lezioni all’Academia Fiorentina circa la figura, sito e la grandezza dell’Inferno di Dante, 1588.https://www.liberliber.it/mediateca/libri/g/galilei/due_lezioni_all_accademia
. A French version, translated by Lucette Degryse: Galilée, Leçons sur l’Enfer de Dante, Fayard, 2008, contains an interesting introduction by the translator, as well as a postface by the present author, containing some technical details omitted here. An English translation by Mark A. Peterson is available at https://www.mtholyoke.edu/courses/mpeterso/galileo/inferno.html.
2. In a letter of 1604 (sixteen years after the publication of the Lessons), a certain Luigi Alamanni complained that he had not been able to obtain communication from the author.
3. Galileo Galilei, Discorsi e dimostrazione matematiche intorno a due nove scienze attenanti alla mecanica & i movimenti locali, 1638. English translation by Stillman Drake, Two New Sciences, University of Wiconsin Press, (1974). https://www.complete-review.com/quarterly/vol3/issue3/galileo.htm
4. See the excellent biography by Ludovico Geymonat, Galileo Galilei, Einaudi, 1957. English translation: L. Geymonat, Galileo Galilei, McGraw Hill, (1965)
5. Benivieni, G.: Dialogo di Antonio Manetti cittadino Fiorentino circa al sito, forma, & misure dello Inferno di Dante Alighieri poeta excellentissimo, Florence: Filippo Giunta, ca. (1506)