By Keith Devlin
By Martin Marsh, Peter Clarke
By Anthony C. Fischer-Cripps (Fischer-Cripps Laboratories Pty Ltd, Sydney, Australia)
By Chris Pearce
By Brian Gaulter, Mark Gaulter
By P. M. Cohn
By George Arfken (Miami University, USA)
By Collins GCSE
By D.J. Heath
By Stephen Doyle, Tony Holloway
By Paul Hoffman
By Christopher J. Cox, D. Bell
By W E Williams & S Y Barham
By Philip Patrick Thorns, Janice Marion King
By Michael J.de Smith
By Kent County Council
By Christopher Jones, Peter Clamp
By Harry Smith
By Thomas A. Garrity (Williams College, Massachusetts), Lori Pedersen
By Philip Kitcher
By Barry Cooper
By School Mathematics Project
By Fentem, Roger, Berry, John, Langham, Sue
By John Bird (Defence College of Technical Training, UK)
By Sue Atkinson, Liz Atkinson