@misc{139926,
  author = {William Martin and Arlene Musgrove and Svetlana Kotochigova and Jean Sansonetti},
  title = {Ground Levels and Ionization Energies for the Neutral Atoms},
  year = {2003},
  month = {2003-01-01},
  publisher = {http://physics.nist.gov/IonEnergy},
  language = {en},
}