@article{AppelfellerLueckert2002,
  author    = {Appelfeller, W. and L{\"u}ckert, A.},
  title     = {Elektronische Marktpl{\"a}tze f{\"u}r Energieversorgungsunternehmen},
  number    = {April},
  year      = {2002},
  language  = {de}
}
@article{AppelfellerLueckert2002,
  author    = {Appelfeller, W. and L{\"u}ckert, A.},
  title     = {Bei Marktpl{\"a}tzen nur kleine Unterschiede},
  series = {ZfK},
  journal   = {ZfK},
  number    = {M{\"a}rz},
  year      = {2002},
  language  = {mul}
}