Susan Stepney Samuel L. Braunstein John A. Clark Andrew M. Tyrrell Andrew Adamatzky Robert E. Smith Thomas R. Addis Colin G. Johnson Jonathan Timmis Peter H. Welch Robin Milner Derek Partridge Journeys in non-classical computation II: initial journeys and waypoints. 97-125 2006 21 IJPEDS 2 http://dx.doi.org/10.1080/17445760500355454 db/journals/paapp/paapp21.html#StepneyBCTASAJTWMP06