Redigerer Titta Ruffo (avsnitt)

== Litteratur ==
* Farkas, Andrew (Ed.),''Titta Ruffo: An Anthology'' (Greenwood Press 1984).
* Hamilton, David, ed., ''The Metropolitan Opera Encyclopedia'' (Simon & Schuster, New York 1987).
* Pleasants, Henry, ''The Great Singers'' (Simon & Schuster, New York 1966).
* Scott, Michael, ''The Record of Singing'', Volume One (Duckworth, London, 1977.)
* Seltsam, William H., ''Metropolitan Opera Annals'' (H.W. Wilson Co., New York 1947).
* Steane, J.B., ''The Grand Tradition'' (Amadeus Press, Portland 1993).
* Tuggle, Robert. ''The Golden Age of Opera'' (Holt, Rinehart, and Winston, 1983).