@article{prestigiacomo1962a, title = {A Frequency Shifter for Improving Acoustic Feedback Stability}, author = {Prestigiacomo, Anthony J. and MacLean, D. J.}, journal = {J. Audio Eng. Soc}, volume = {10}, number = {2}, pages = {110--113}, year = {1962}, url = {https://www.aes.org/e-lib/browse.cfm?elib=866} }