@article{schulten:1975:sca,
    author = {Schulten, Klaus and Gordon, Roy G.},
     title = {Semiclassical approximations to {$3j$}- and
              {$6j$}-coefficients for quantum-mechanical coupling of angular
              momenta},
   journal = {J. Mathematical Phys.},
    volume = {16},
      year = {1975},
    number = {10},
     pages = {1971–1988},
   mrclass = {81.65},
  mrnumber = {MR0381598 (52 \#2491)},
mrreviewer = {J.-L. Calais},
       doi = {10.1063/1.522427}}