@article{Petsche2010,
  author    = {Petsche, Hans-Joachim},
  title     = {It began with Pestalozzi and Schleiermacher : Reflections on the polymath Hermann Grassmann (1809 - 1877)},
  issn      = {1027-488x},
  year      = {2010},
  language  = {en}
}