some background i found on a quick search: http://www.maa.org/mathland/mathtrek_6_28_99.html http://www.maa.org/mathland/mathtrek_6_28_99.html (short summary)

some background i found on a quick search: http://www.maa.org/mathland/mathtrek_6_28_99.html http://www.maa.org/mathland/mathtrek_6_28_99.html (short summary) http://www.maths.bris.ac.uk/~majm/bib/GAFoS.pdf http://www.maths.bris.ac.uk/~majm/bib/GAFoS.pdf (two page magazine article) http://www.maths.bris.ac.uk/~majpk/papers/67.pdf http://www.maths.bris.ac.uk/~majpk/papers/67.pdf (heavier)