1. R.C. Titsworth, “Correlation Properties of Cyclic Sequences”, Thesis, California Inst. of Technology, Pasadena, California, 1962.
2. M.G. Karpovsky, “Finite Orthogonal Series in the Design of Digital Devices”, New York and Jerusalem, Wiley and IVP, 1976.
3. R.J. Lechner, “Harmonic Analysis of Switching Functions”, in “Recent Developments in Switching Theory”, edited by A. Mukhopadhyay, Academic Press, New York and London, 1971.