@book{PetscheKannenbergKessleretal.2009,
  author    = {Hans-Joachim Petsche and Lloyd Kannenberg and Gottfried Kessler and Jolanta Liskowacka},
  title     = {Hermann Grassmann - Roots and traces : autographs and unknown documents},
  volume    = {2},
  isbn      = {978-3-0346-0154-2},
  doi       = {10.1007/978-3-0346-0155-9},
  year      = {2009},
}