APA (7th ed.) Citation

Petrarca, F., Bernardo, A. S., Levin, S., & Bernardo, R. A. (2005). Letters of old age =: (Rerum senilium libri) (First paperback edition.). Italica.

Chicago Style (17th ed.) Citation

Petrarca, Francesco, Aldo S. Bernardo, Saul Levin, and Reta A. Bernardo. Letters of Old Age =: (Rerum Senilium Libri). First paperback edition. New York: Italica, 2005.

MLA (8th ed.) Citation

Petrarca, Francesco, et al. Letters of Old Age =: (Rerum Senilium Libri). First paperback edition. Italica, 2005.