Jerome Roche/Noel O’Regan: Allegri, Gregorio. In: Grove Music Online. Oxford Music Online. Oxford University Press, Version: 20. Januar 2001. http://www.oxfordmusiconline.com.
Jerome Roche/Noel O’Regan: Allegri, Gregorio. In: Grove Music Online. Oxford Music Online. Oxford University Press, Version: 20. Januar 2001. http://www.oxfordmusiconline.com.