@article{riggs1962a, title = {A Two Speaker, Acoustically Coupled, Single Enclosure Stereo System}, author = {Riggs, John H.}, journal = {J. Audio Eng. Soc}, volume = {10}, number = {4}, pages = {294--297}, year = {1962}, url = {https://www.aes.org/e-lib/browse.cfm?elib=839} }