@article{barnett:1981:ari,
    author = {Barnett, A. R.},
     title = {An algorithm for regular and irregular {C}oulomb and {B}essel
              functions of real order to machine accuracy},
   journal = {Comput. Phys. Comm.},
  fjournal = {Computer Physics Communications},
    volume = {21},
      year = {1981},
    number = {3},
     pages = {297–314},
       doi = {10.1016/0010-4655(81)90011-4}}