1. Department of Mathematics, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom, , http://personal.maths.surrey.ac.uk/st/H.Bruin/
2. Mathematical Institute, School of Mathematics and Statistics, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9SS, United Kingdom, http://www.mcs.st-and.ac.uk/~miket/index.html