Petrus H. Potgieter, Elemér E. Rosinger. Ultrafilter and Non-standard Turing Machines. In Cristian S. Calude, José Félix Costa, Rudolf Freund, Marion Oswald, Grzegorz Rozenberg, editors, Unconventional Computing, 7th International Conference, UC 2008, Vienna, Austria, August 25-28, 2008. Proceedings. Volume 5204 of Lecture Notes in Computer Science, pages 220-227, Springer, 2008. [doi]
Abstract is missing.