Weinstock 1963, pp. 231–232. Weinstock, Herbert (1963). Donizetti and the World of Opera in Italy, Paris, and Vienna in the First Half of the Nineteenth Century. New York: Pantheon Books. LCCN63013703.
"Music: Donizetti Revived", Time, 22 June 1959: "In a publisher's warehouse in Milan last fall, Kalamazoo-born conductor Thomas Schippers discovered an opera score dedicated to Queen Margherita of Italy and tied up in purple string. In Spoleto last week, at the opening of Gian Carlo Menotti's Festival of Two Worlds, he unwrapped his find before a capacity audience. Italian critics promptly hailed the long-forgotten work as one of the finest creations of composer Gaetano Donizetti". Retrieved 9 February 2014.
