@unpublished{Lukaschewitsch2007,
  author  = {Michael Lukaschewitsch},
  title   = {Geoelectrical conductivity problems on unbounded domains},
  institution = {Institut f{\"u}r Physik und Astronomie},
  series    = {NLD Preprints},
  number    = {45},
  year    = {2007},
}