M. Dittenbach, D. Merkl, A. Rauber:
"Serendipity in text and audio information spaces: {O}rganizing and exploring high-dimensional data with the growing hierarchical self-organizing map";
in: "Classification and Clustering for Knowledge Discovery", S. Halgamuge, L. Wang (ed.); Springer, Germany, 2005, ISBN: 3-540-26073-0, 43 - 60.