@article{takahashi1975noise, title = {Noise Reduction in the CD-4 Disc System}, author = {Takahashi, Nobuaki and Muraoka, Teruo and Inoue, Toshiya}, journal = {J. Audio Eng. Soc}, volume = {23}, number = {2}, pages = {113--122}, year = {1975}, url = {https://www.aes.org/e-lib/browse.cfm?elib=2709} }