The Phonofilm, (ed.) Lee DeForest , exh. cat. Transactions of the Society of Motion Picture Engineers (1923)

@article{DeForest.1923,
 author = {DeForest, Lee},
 year = {1923},
 title = {The Phonofilm},
 pages = {61-75},
 number = {16},
 journal = {Transactions of the Society of Motion Picture Engineers}
}