@book{PetscheLewisLiesenetal.2011,
  author    = {Petsche, Hans-Joachim and Lewis, Albert C. and Liesen, J{\"o}rg and Russ, Steve},
  title     = {Hermann Grassmann - from past to future : Grassmann's work in context ; Grassmann Bicentennial Conference, September 2009},
  series = {Grassmann-Trilogie},
  volume    = {3},
  journal   = {Grassmann-Trilogie},
  publisher = {Birkh{\"a}user},
  address   = {Basel},
  isbn      = {978-3-0346-0404-8},
  pages     = {XX, 580 S. : Ill., graph. Dars},
  year      = {2011},
  language  = {en}
}
@book{PetscheKannenbergKessleretal.2009,
  author    = {Petsche, Hans-Joachim and Kannenberg, Lloyd and Kessler, Gottfried and Liskowacka, Jolanta},
  title     = {Hermann Grassmann - Roots and traces : autographs and unknown documents},
  series = {Grassmann-Trilogie},
  volume    = {2},
  journal   = {Grassmann-Trilogie},
  publisher = {Birkh{\"a}user Basel},
  address   = {Basel},
  isbn      = {978-3-0346-0154-2},
  doi       = {10.1007/978-3-0346-0155-9},
  pages     = {XI; 256 S.; Ill.},
  year      = {2009},
  language  = {en}
}