Dr. W. Reinecke: Die Kunst der idealen Tonbildung. Leipzig, 1906.
William Shakespeare: The Art of Singing. London, 1898.
G. B. Lamperti: The Technics of Bel Canto. New York, 1905.
Paolo Guetta: Il Canto nel suo Mecanismo. Milan, 1902.
Lilli Lehmann: Meine Gesangskunst. Berlin, 1902.
David Frangçon-Davies: The Singing of the Future. London, 1906.
Leo Kofler: The Old Italian Method. Albany, 1880.
The Art of Breathing. New York, 1889.
Clara Kathleen Rogers: The Philosophy of Singing. New York, 1893.
Albert B. Bach: The Principles of Singing. London (2d ed.), 1897.