@incollection{BaxHeidemannRitter2005,
  author    = {Bax, I. and Heidemann, G. and Ritter, H.},
  title     = {Using Non-negative Sparse Profiles in a Hierarchical Feature Extraction Network},
  series = {Proc. 9th IAPR Conf. Machine Vision Applications},
  booktitle = {Proc. 9th IAPR Conf. Machine Vision Applications},
  address   = {Tsukuba Science City, Japan},
  pages     = {464 -- 467},
  year      = {2005},
  language  = {mul}
}
@incollection{HeidemannBaxBekeletal.2004,
  author    = {Heidemann, G. and Bax, I. and Bekel, H. and Bauckhage, C. and Wachsmuth, S. and Fink, G. and Pinz, A. and Ritter, H. and Sagerer, G.},
  title     = {Multimodal interaction in an augmented reality scenario},
  series = {Proc. Int'l Conf. Multimodal Interfaces},
  booktitle = {Proc. Int'l Conf. Multimodal Interfaces},
  address   = {New York, NY, USA},
  pages     = {53 -- 60},
  year      = {2004},
  language  = {mul}
}
@incollection{HeidemannBekelBaxetal.2004,
  author    = {Heidemann, G. and Bekel, H. and Bax, I. and Ritter, H.},
  title     = {Interactive Online Learning},
  series = {Proc. Pattern Recognition and Image Analysis},
  booktitle = {Proc. Pattern Recognition and Image Analysis},
  address   = {St. Petersburg, Russia},
  pages     = {44 -- 48},
  year      = {2004},
  language  = {mul}
}