@article{barnett:1981:kcf,
    author = {Barnett, A. R.},
     title = {{KLEIN:} {C}oulomb functions for real $\lambda$ and positive
              energy to high accuracy},
   journal = {Comput. Phys. Comm.},
  fjournal = {Computer Physics Communications},
    volume = {24},
      year = {1981},
    number = {2},
     pages = {141–159},
      note = {Double-precision Fortran code for positive energies.},
       doi = {10.1016/0010-4655(81)90088-6},
     links = {\URL[Code]{http://cpc.cs.qub.ac.uk/summaries/ABNJ}}}