By Russell, Andy
By Susie Jameson, Jameson, Susie
By Winston, Patrick Henry
By Stroud, K. A., K. A. Stroud
By Waltham, David
By N/A
By Poskitt, Kjartan, Watson, Richard
By Humphrey, Douglas, Topping, James
By Keith Pledger, John Hebborn, Jean Littlewood
By Bird, John O., May, A. J. C.
By Smullyan, Raymond M.
By Gillham, Bill, Burgess, Mark
By Sanders, Paul
By Hewlett, Gill
By The Spode Group, Berry, John, Burghes, D. N., Huntley, Ian
By Kangaroo Maths, JustMaths
By Cooper, Richard
By Woodward, Kath
By Gilder, Jules H.
By Ken Hoyle
By Farrow, L., Llewellyn, S.
By Weltner, K., Weber, W.J., Grosjean, J., Schuster, P., Grosjean, J., Schuster, P.
By Parhami, Behrooz
By McArthur, Charles W.
By Heylings, M. R.
By G. Marshall
By Magnello, Eileen