Kaufman 1997: For example, Il giuramento received 400 performances and La vestale 150 compared to Giovanna d'Arco, Don Carlo (in all its versions), and Aroldo's approx. 90 each. Kaufman, Thomas G. (June 1997). "Mercadante and Verdi". The Opera Quarterly. 13 (3): 41–56. doi:10.1093/oq/13.3.41.