Structure in Complexity Theory Conference, 1988. Proceedings., Third Annual (1988), pp. 112-115.
J. ACM, Vol. 46, No. 2. (March 1999), pp. 185-211.
J. ACM, Vol. 14, No. 2. (April 1967), pp. 322-336.
(1972), pp. 85-103.
(1973), pp. 1-9.
Fundam. Inf., Vol. 58, No. 2. (April 2003), pp. 67-77.
Theoretical Computer Science, Vol. 369, No. 1-3. (15 December 2006), pp. 211-229.
(1971), pp. 151-158.
Natural Computing, Vol. 2, No. 3. (2003), pp. 287-298.
Algorithms – ESA 2005 (2005), pp. 71-82.
pp. 289-301.
Structure in Complexity Theory Conference, 1992., Proceedings of the Seventh Annual (1992), pp. 107-110.
STACS 2004 (2004), pp. 31-43.
(1987), pp. 123-131.
(13 December 1996)
(15 January 1979)
(30 November 1993)
Membrane Computing (2006), pp. 224-240.
DNA Computing (2006), pp. 33-46.
(January 2007)
(1972), pp. 187-192.
Unconventional Computation (2007), pp. 62-76.
American Journal of Mathematics, Vol. 57, No. 3. (1935), pp. 509-533.
(2001)
(28 April 1977)
Membrane Computing (2005), pp. 85-109.
Natural Computing, Vol. 2, No. 3. (2003), pp. 265-285.
Computational Complexity, Vol. 7, No. 1. (2 July 1998), pp. 54-97.
(1969), pp. 143-148.
(1997)
Mathematics Magazine, Vol. 69, No. 4. (1996), pp. 261-266.
Automata, Languages and Programming (2000), 199.
Journal of Computer and System Sciences, Vol. 73, No. 1. (February 2007), pp. 137-152.
(September 2006)