@article{UlrichsKuhlencordtMuellerRuchholtz1979,
  author    = {Karin Ulrichs and KM Kuhlencordt and W. M{\"u}ller-Ruchholtz},
  title     = {Plating inhibition assay (PIA): a new test for cell mediated cytotoxicity},
  year      = {1979},
}