A true mirror of sound : Bettini micro-phonograph, micro-diaphragms for phonograph and graphophone, Bettini celebrated "opera musical records" and autograph-records of world famous artists

Bettini Phonograph Laboratory · 1900 · New York : Bettini Phonograph Laboratory · 8 pictures

Trade catalogs · Sound recordings · Phonograph · Bettini Phonograph Laboratory

Internet Archive · Smithsonian Libraries · Public domain (published before 1931) · More from this library