@article{bushman1958transistorized, title = {Transistorized Magnetic and Photoelectric Input Circuits for Motion Picture Projectors}, author = {Bushman, Stephen F.}, journal = {J. Audio Eng. Soc}, volume = {6}, number = {1}, pages = {4--9}, year = {1958}, url = {https://www.aes.org/e-lib/browse.cfm?elib=250} }