@article{kolbig:1972:pcl,
    author = {K{\"o}lbig, K. S.},
     title = {Programs for computing the logarithm of the gamma function, and the
              digamma function, for complex argument},
   journal = {Comput. Phys. Comm.},
  fjournal = {Computer Physics Communications},
    volume = {4},
      year = {1972},
     pages = {221–226},
      note = {Single-precision Fortran, accuracy 12-14S},
       doi = {10.1016/0010-4655(72)90012-4},
     links = {\URL[Code]{http://cpc.cs.qub.ac.uk/summaries/ACRG}}}