1. Colin M. Campbell, George Havas, Colin Ramsay, and Edmund F. Robertson, Nice efficient presentations for all small simple groups and their covers, LMS J. Comput. Math. 7 (2004), 266–283 (electronic).[MR]
  2. Colin M. Campbell, George Havas, Colin Ramsay, and Edmund F. Robertson, On the efficiency of the simple groups of order less than a million and their covers, Experiment. Math. 16 (2007), no. 3, 347–358.[MR]
  3. Marston Conder, George Havas, and Colin Ramsay, Efficient presentations for the Mathieu simple group M22 and its cover, Finite geometries, groups, and computation, Walter de Gruyter GmbH &Co. KG, Berlin, 2006, pp. 33–41.[MR]
  4. George Havas and Colin Ramsay, Proving a group trivial made easy: A case study in coset enumeration, Bull. Austral. Math. Soc. 62 (2000), no. 1, 105–118.[MR]
  5. George Havas and Colin Ramsay, Short balanced presentations of perfect groups, Groups St. Andrews 2001 in Oxford. Vol. I, London Math. Soc. Lecture Note Ser., vol. 304, Cambridge Univ. Press, Cambridge, 2003, pp. 238–243.[MR]
  6. George Havas and Colin Ramsay, On proofs in finitely presented groups, Groups St. Andrews 2005. Vol. 2, London Math. Soc. Lecture Note Ser., vol. 340, Cambridge Univ. Press, Cambridge, 2007, pp. 457–474.[MR]
  7. Colin Ramsay, Trades and defining sets: theoretical and computational results, PhD Thesis, University of Queensland, 1998.