@article{ashly1971operational, title = {Operational Amplifier Implementation of Ideal Electronic Crossover Networks}, author = {Ashly, J. Robert and Henne, Lawrence M.}, journal = {J. Audio Eng. Soc}, volume = {19}, number = {1}, pages = {7--11}, year = {1971}, url = {https://www.aes.org/e-lib/browse.cfm?elib=2215} }