@article{156731,
  author = {James Sims and Stanley Hagstrom},
  title = {High Precision Hy-CI Variational Calculations for the Ground State of Neutral Helium and Helium-Like ions},
  year = {2002},
  number = {90},
  month = {2002-04-01},
  publisher = {International Journal of Quantum Chemistry},
  url = {https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=150834},
  language = {en},
}