@Article{RSM:Cra87b,
  author =       "E. Cramer and D. McManus and D. Neubert",
  title =        "Estimnation and Removal of Power Line Interference in
                 the Electrocardiogram: {A} Comparison of Digital
                 Approaches",
  journal =      j-CBR,
  year =         "1987",
  volume =       "2",
  pages =        "12--28",
  robnote =      "Haven't read it yet but for filters, signal
                 processing, etc. it may be interesting. A product of
                 the PTB Berlin., ECG061",
}