@unpublished{Eckstein2006,
  author    = {Eckstein, Lars},
  title     = {Performing jazz, defying essence},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-85574},
  pages     = {15},
  year      = {2006},
  language  = {en}
}