Dynamical Systems and Small Divisors Lectures given at the C.I.M.E. Summer School held in Cetraro Italy, June 13-20, 1998 - Eliasson, Hakan; Eliasson, Hakan; Kuksin, Sergei; Marmi, Stefano; Yoccoz, Jean-Christophe (Springer Berlin Heidelberg : Imprint: Springer, 2002)