Black, Robert (2011) Notes on the date and genesis of Machiavelli's De principatibus. In: Europa e Italia. Studi in onore di Giorgio Chittolini = Europe and Italy. Studies in honour of Giorgio Chittolini. Reti Medievali E-Book (15). Firenze University Press, Firenze, pp. 29-41. ISBN 978-88-6453-234-9