@misc{139911,
  author = {William Martin and Arlene Musgrove},
  title = {Ground Levels and Ionization Energies for the Neutral Atoms},
  year = {1998},
  month = {1998-01-01},
  publisher = {http://physics.nist.gov/PhysRefData/IonEnergy/ionEnergy.html},
  language = {en},
}