Duin, Robert P. W.; de Ridder, Dick; Tax, David M. J.:
Featureless pattern classification.
(English).Kybernetika,
vol. 34
(1998),
issue 4,
pp. [399]-404
Lisoněk, Petr:
On related transducers.
(English).Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica,
vol. 29
(1990),
issue 1,
pp. 291,292-299