(en) « George Eash CARtridge inventor tells how it was born », Billboard, vol. 78, no 10, (lire en ligne, consulté le )
goldminemag.com
(en) « Collector's Corner: The History of the Eight-Track Tape », sur goldminemag.com (consulté le ) : « Just as the signs were all pointing to eight-track toppling vinyl as the format of choice for music lovers in the United States, Canada and to a lesser extent, in Great Britain, along came the audio cassette »