Grove.—Dictionary of Music and Musicians, articles on the Clavichord,
Virginal, Spinet, Harpsichord, Pianoforte.
Naumann.—History of Music, Vol. I.
Weitzmann.—History of the Pianoforte.
Brinsmead.—History of the Pianoforte.
Rimbault.—The Pianoforte: Its Origin, Progress and Construction.
Spillane.—History of the American Pianoforte.