Nonlinear laser spectroscopy - Atkins, C; Hancock, G; Zacharias, H; Beverini, N; Galli, M; Inguscio, M; Strumia, F; Bionducci, G; Bloomfield, L; Gerhardt, H; Hänsch, T; Boulnois, J; et al. (Springer-Verlag, 1982)