@article{inoue1971a, title = {A Discrete Four-Channel Disc and Its Reproducing System (CD-4 System)}, author = {Inoue, Toshiya and Takahashi, Nobuaki and Owaki, Isao}, journal = {J. Audio Eng. Soc}, volume = {19}, number = {7}, pages = {576--583}, year = {1971}, url = {https://www.aes.org/e-lib/browse.cfm?elib=2152} }