@article{LeipoldFichtnerHeberetal.2006,
  author    = {Leipold, M. and Fichtner, H. and Heber, B. and Groepper, P. and Lascar, S. and Burger, F. and Eiden, M. and Niederstadt, T. and Sickinger, C. and Herbeck, L. and Dachwald, Bernd and Seboldt, W.},
  title     = {Heliopause Explorer - A Sailcraft Mission to the Outer Boundaries of the Solar System},
  series = {Acta Astronautica. 59 (2006), H. 8-11},
  journal   = {Acta Astronautica. 59 (2006), H. 8-11},
  isbn      = {0094-5765},
  pages     = {786 -- 796},
  year      = {2006},
  language  = {en}
}
@article{DachwaldSeboldtRichter2006,
  author    = {Dachwald, Bernd and Seboldt, W. and Richter, L.},
  title     = {Multiple rendezvous and sample return missions to near-Earth objects using solar sailcraft / Dachwald, B. ; Seboldt, W. ; Richter, L.},
  series = {Acta Astronautica. 59 (2006), H. 8-11},
  journal   = {Acta Astronautica. 59 (2006), H. 8-11},
  isbn      = {0094-5765},
  pages     = {768 -- 776},
  year      = {2006},
  language  = {en}
}