By The Math Forum, Jessica Wolk-Stanley
By Green, Dan, Basher, Simon
By Hirst, Keith
By Abbott, Paul, Wardle, Michael
By Kirkby, Dave, Dave Kirkby
By Pate, Katherine
By Oliver, Diane
By School Mathematics Project
By Owen, Annie
By Merttens BA MED, Ruth
By Brodie, Andrew
By Heylings, M. R.
By Pratt, Kathy, Kirby, Elizabeth
By Hunter, John, Scottish Mathematics Group, Monk, David
By The 11+ Company, Richard E. Martin
By Vorderman, Carol
By Poskitt, Kjartan, Reeve, Philip
By John Mason, Alan Graham, Sue Johnston-Wilder
By Nicholson, Su
By Various
By Books, CGP
By Webber, B., Barnes, T.
By Dickinson, Paul, Hough, Susan, Eade, Frank, Gough, Steve, Dudzic, Stella
By Michael Cornelius
By Saxon, John H., Jr.
By Steve Mills, Hilary Koll