1. H. Beker and F. Piper, Cipher Systems. London: Northwood Books, 1982.
2. S.W. Golomb, Shift register sequences. Revised edition, Laguna Hills, California: Aegean Park Press, 1982.
3. E.L. Key, “An analysis of the structure and complexity of nonlinear binary sequence generators”, IEEE Trans.Inform.Theory, vol. IT-22, pp. 732–736, Nov. 1976.
4. S.H. Tsao, “Generation of delayed replicas of maximal-length linear binary sequences”, Proc. IEEE, vol. 111, pp. 1803–1806, Nov. 1964.
5. J. Bernasconi and C.G. Günther, “Analysis of a nonlinear feed-forward logic for binary sequence generators”, submitted to IEEE Trans.Inform.Theory.