Beckmann, Arnold..Logical approaches to computational barriers : Second Conference on Computability in Europe, CiE 2006, Swansea, UK, June 30-July 5, 2006 : proceedings /.Springer,,c2006..
Logical approaches to computational barriers : Second Conference on Computability in Europe, CiE 2006, Swansea, UK, June 30-July 5, 2006 : proceedings /