@article{HerrmannLippke1999,
  author    = {Herrmann, Ulf and Lippke, F.},
  title     = {The influence of transients on the design of DSG solar fields},
  series = {Journal de Physique IV : proceedings},
  volume    = {9},
  journal   = {Journal de Physique IV : proceedings},
  number    = {PR3},
  isbn      = {2-86883-402-7},
  issn      = {1764-7177 (Online)},
  doi       = {10.1051/jp4:1999377},
  pages     = {489 -- 494},
  year      = {1999},
  language  = {en}
}
@article{HerrmannNava2005,
  author    = {Herrmann, Ulf and Nava, P.},
  title     = {Die Strahlung der Sonne einfangen},
  series = {DLR-Nachrichten / Deutsches Zentrum f{\"u}r Luft- und Raumfahrt},
  volume    = {109},
  journal   = {DLR-Nachrichten / Deutsches Zentrum f{\"u}r Luft- und Raumfahrt},
  number    = {Sonderheft Solarforschung},
  issn      = {0937-0420},
  pages     = {34 -- 37},
  year      = {2005},
  language  = {de}
}