@book{BraunFeudelSeehafer1997,
  author    = {Braun, Robert and Feudel, Fred and Seehafer, Norbert},
  title     = {Bifurcations and chaos in an array of forced vortices},
  series = {Preprint NLD},
  volume    = {37},
  journal   = {Preprint NLD},
  publisher = {Univ. Potsdam},
  address   = {Potsdam},
  issn      = {1432-2935},
  pages     = {7 S. : graph. Darst.},
  year      = {1997},
  language  = {en}
}
@book{BraunFeudelGuzdar1998,
  author    = {Braun, Robert and Feudel, Fred and Guzdar, P.},
  title     = {The route to chaos for a two-dimensional externally driven flow : [to appear in Physical Review E]},
  series = {Preprint NLD},
  volume    = {46},
  journal   = {Preprint NLD},
  publisher = {Univ. Potsdam},
  address   = {Potsdam},
  issn      = {1432-2935},
  pages     = {7 S. : graph. Darst.},
  year      = {1998},
  language  = {en}
}