@article{SchwarzBenzKurthsetal.1993,
  author    = {udo Schwarz and Arnold O. Benz and J{\"u}rgen Kurths and Annette Witt},
  title     = {Analysis of solar spike events by means of symbolic dynamics methods},
  url       = {http://www.astro.phys.ethz.ch/papers/benz/schwarz/schwarz/schwarz.html},
  year      = {1993},
}