Noncommutative geometry : lectures given at the C.I.M.E. Summer School held in Martina Franca, Italy, September 3-9, 2000 - C.I.M.E. Summer School; Connes, Alain; Cuntz, Joachim J. R.; Guentner, Erik; Higson, N.; Kaminker, Jerome; Roberts, J. E.; Doplicher, S. (Sergio); Longo, Roberto; Zecca, P. (Pietro) (Lecture notes in mathematics, 2004)