N. Masuda, Master thesis, Department of Mathematical Engineering and
Information Physics, School of Engineering, the University of Tokyo, 2000
(submitted to IEEE Trans. CAS I).
(3) Naoki Masuda and Kazuyuki Aihara, ``Chaotic Cryptosystems using
discretized chaotic maps'',
Computer Today, Saiensu-sha, pp. 14-20, May, 2000 (in Japanese).