@article{10506,
  author = {W. Robb and Michael Meadows and T. Burnett and Gary Doolen},
  title = {R-matrix calculation of third-order optical harmonic coefficients of atomic hydrogen and helium},
  year = {1977},
  journal = {Physical Review A},
  volume = {15},
  pages = {1063-1067},
  month = {Jan-03-1977},
  issn = {0556-2791},
  url = {http://link.aps.org/doi/10.1103/PhysRevA.15.1063},
  doi = {10.1103/PhysRevA.15.1063},
}