Cristian S. Calude José Félix Costa Nachum Dershowitz Elisabete Freire Grzegorz Rozenberg Unconventional Computation, 8th International Conference, UC 2009, Ponta Delgada, Azores, Portugal, September 7-11, 2009. Proceedings 5715 2009 http://dx.doi.org/10.1007/978-3-642-03745-0 978-3-642-03744-3 Lecture Notes in Computer Science Springer db/conf/uc/uc2009.html