@misc{VotziHimmelstossErtl,
  author    = {Votzi, Helmut and Himmelstoß, Felix and Ertl, Hans},
  title     = {Hybrid Filter for a Multi-Cell Switch-Mode Power Amplifier},
  subject      = {Power Amplifier},
  language  = {en}
}
@misc{VotziHimmelstossErtl,
  author    = {Votzi, Helmut and Himmelstoß, Felix and Ertl, Hans},
  title     = {Active Hybrid Filter Applied with a Multi-Cell Switch-Mode Power Amplifier},
  subject      = {Switch-mode power amplifier},
  language  = {en}
}