Garbe, C S, Krajsek, K, Pavlov, P, Andres, B, Mühlich, M, Stuke, I, Mota, C, Böhme, M, Haker, M, Schuchert, T, Scharr, H, Aach, T and Barth, E (2008). Nonlinear Analysis of Multi-Dimensional Signals. Mathematical Methods in Signal Processing and Digital Image Analysis. Springer. 231-288