By Sole, Puzzles Numbers and Infinity Tim
By Phillips, Richard
By Jenkins, Adrian
By Mullins, Roy
By Taylor, Don
By Matthew Syed
By Bartlett, Roger
By Gardner, Martin
By Sachar, Louis
By Jenny Tyler, Graham Round
By Dunn, Angela Fox
By Haselbauer, Nathan
By Devadas, Srini
By Noaa, N/A
By Pinel, Adrian, Pinel, Jeni
By Michael Holt and Zoltan Dienes
By Fogle, Ben
By Weinberg, Steven
By Straker, Anita
By Wilson, Robin
By Tyler, Jenny, Round, Graham
By Kirkby, David
By ApSimon, Hugh
By Lennart Rade and Burt a.Kaufman
By Kelsey, Kenneth
By Gould, Mr Mike
By Roeder, Oliver