David E. Rydeheard Donald Sannella A Collection of Papers and Memoirs Celebrating the Contribution of Rod Burstall to Advances in Computer Science. 187-193 2002 13 Formal Asp. Comput. 3-5 http://link.springer.de/link/service/journals/00165/bibs/2013003/20130187.htm db/journals/fac/fac13.html#RydeheardS02