By Hubert Smith
By A. Nicolaides
By A. Nicolaides, Nicolaides, A.
By Ian Lucas, Lucas, Ian
By David E Hanson
By A. Jedrosz, J. Watts, Susan Loxley
By The UK Mathematics Trust
By Allison Lee
By Mark Davies, Anthony Cook, Brian Rushton
By Daydream Education
By Steve Langfield
By Nathan Goodman
By Various
By Sue Jennings
By Michael White, White, Michael
By PROMPT Maternity Foundation
By Ashby Merson-Davies
By Kumon Publishing
By Sherrill B Flora
By Paul Preuss
By Martin Bluemel
By Stephen Doyle
By R Mitchell
By Pedigree Books Ltd
By James Dale-Adcock