@article{Burckel1994,
  author    = {{Serge Burckel}},
  title     = {{Functional equations associated with congruential functions}},
  journal   = {{Theoretical Computer Science}},
  year      = {{1994}},
  volume    = {{123}},
  pages     = {{397--406}},
  note      = {{MR 94m.11147}},
}