Automorphic forms on GL(2).- The differential equations satisfied by Whittaker functions.- Jacquet's Whittaker functions.- Fourier expansions of automorphic forms.- Invariants of G?\G.- Ramanujan sums on GL(3).- Eisenstein series.- The analytic continuation and functional equations satisfied by the L-series associated with an automorphic form.- Hecke operators and L-series.- The Mellin transforms of the Whittaker functions.