By Gifford, Paul
By Williams, R. R.
By Leaney, A.R. Leaney
By Cook, Helen, Styles, Morag
By School Mathematics Project
By Hicks, Diana, Pote, Michael, Esnol, Armel, Wright, Derek
By McRae, John, Boardman, Roy
By WHITBY, Norman
By Boesch, Christophe
By Forey, P. L., Greenwood, P. H.
By Moore, N
By O'Dell, Felicity
By Jones, Leo
By Fage, J. D.
By Cambridge ESOL
By Jakeman, Vanessa, McDowell, Clare
By Schraeder, Peter J.
By Wyse, Akintola
By O'Brien, Donal Cruise, Dunn, John, Rathbone, Richard
By Barry, Boubacar
By David and Helen Kimble etc
By Davies, R. W.
By Skinner, Quentin
By Matthewman, Jim
By White, Anita