Phonograph — Audiobooks
Le Téléphone, le Microphone et le Phonographe
by comte Th. Du Moncel
Development of the Phonograph at Alexander Graham Bell's Volta Laboratory Contributions from the Museum of History and Technology, United States National Museum Bulletin 218, Paper 5, (pages 69-79)
by Leslie J. Newville
The telephone, the microphone & the phonograph
by comte Th. Du Moncel