am References

Copyright WDC C1 for STP at RAL.

• Indices Kn, Ks, Km (1964 - 1967)
  CNRS, pages 156, Paris 1968.
  Author Mayaud, P.N.
• Derivation, Meaning, and Use of Geomagnetic Indices
  AGU (Washington D.C.), 1980.
  Author Mayaud, P.N.