Susan Stepney Samson Abramsky Andy Adamatzky Colin G. Johnson Jon Timmis Grand Challenge 7: Journeys in Non-Classical Computation. 407-421 2008 BCS Int. Acad. Conf. http://www.bcs.org/server.php?show=ConWebDoc.22984 conf/bcs/2008 db/conf/bcs/bcs2008.html#StepneyAAJT08