By McDuell, Mr Bob
By Burton, George, Holman, John, Pilling, Gwen, Waddington, David
By York Science Education Group, The University of
By Tracy Traynor
By Gale, MR Peter
By Murray, Robin, Filer, Denis
By Marland, Michael, etc.
By Stenhouse, Lawrence
By Stenhouse, L.
By Edwards, Roy, Edwards, Mary, Ward, Alan
By School Mathematics Project
By Bolt, Brian
By Dunn, Jennifer, Styles, Morag, Warburton, Nick