@article{newman1973a, title = {A Loudspeaker System Design Utilizing a Sixth-Order Butterworth Response Characteristic}, author = {Newman, Raymond J.}, journal = {J. Audio Eng. Soc}, volume = {21}, number = {6}, pages = {450--456}, year = {1973}, url = {https://www.aes.org/e-lib/browse.cfm?elib=1957} }