References — Frequency Transformations
 Constantinides, A.G., “Spectral Transformations for Digital Filters,” IEEE Proceedings, Vol. 117, No. 8, pp. 1585-1590, August 1970.
 Nowrouzian, B., and A.G. Constantinides, “Prototype Reference Transfer Function Parameters in the Discrete-Time Frequency Transformations,” Proceedings 33rd Midwest Symposium on Circuits and Systems, Calgary, Canada, Vol. 2, pp. 1078-1082, August 1990.
 Feyh, G., J.C. Franchitti, and C.T. Mullis, “Allpass Filter Interpolation and Frequency Transformation Problem,“ Proceedings 20th Asilomar Conference on Signals, Systems and Computers, Pacific Grove, California, pp. 164-168, November 1986.
 Krukowski, A., G.D. Cain, and I. Kale, “Custom Designed High-Order Frequency Transformations for IIR Filters,” 38th Midwest Symposium on Circuits and Systems (MWSCAS'95), Rio de Janeiro, Brazil, August 1995.