Kumiko Maebashi Nobuo Suematsu Akira Hayashi Component Reduction for Hierarchical Mixture Model Construction. 326-335 2007 ICONIP (2) http://dx.doi.org/10.1007/978-3-540-69162-4_34 conf/iconip/2007-2 db/conf/iconip/iconip2007-2.html#MaebashiSH07