Letters to his wife
MLA
Busoni, Ferruccio and Gerda Busoni. Letters to his wife. New York : Da Capo Press, 1975.
APA
Busoni, F. & Busoni, G. (1975). Letters to his wife. New York : Da Capo Press.
Chicago
Busoni, Ferruccio and Gerda Busoni. Letters to his wife. New York : Da Capo Press, 1975.