Pei, Soo-Chang; Chang, Ja-Han; Ding, Jian-Jiun (2004-06-21). “Commutative reduced biquaternions and their Fourier transform for signal and image processing”. IEEE Transactions on Signal Processing (IEEE) 52 (7): 2012-2031. doi:10.1109/TSP.2004.828901. ISSN1941-0476.
Pei, Soo-Chang; Chang, Ja-Han; Ding, Jian-Jiun (2004-06-21). “Commutative reduced biquaternions and their Fourier transform for signal and image processing”. IEEE Transactions on Signal Processing (IEEE) 52 (7): 2012-2031. doi:10.1109/TSP.2004.828901. ISSN1941-0476.