Planetary Magnetic Activity indices 
    (aa, Kpa, am, Kpm, Dst, AE, ssc, Sfe, Kp, Quiet days) 
            International Service of Geomagnetic Indices 
            ISGI, EOST - 5 rue René Descartes,
            F-67084 Strasbourg cedex, FRANCE

Planetary Magnetic Activity indices 
    (Kp, ap, Ap, Cp, C9) are derived by:
            GeoForschungsZentrum Potsdam
             Helmholtz-Zentrum Potsdam Deutsches,
             GeoForschungsZentrum GFZ, Telegrafenberg,
             14473 Potsdam, GERMANY

Auroral Electrojet indices (AE, AL, AU, AO)
Disturbance Storm Time index (Dst)
Ring Current indices (SYM, ASY) are derived by:
            World Data Center for Geomagnetism
            Graduate School of Science, Kyoto University,
            Kitashirakawa-Oiwake Cho, Sakyo-ku,
            Kyoto 606-8502, JAPAN     

Northern PC-indices (1 min and 15 min PCN)are derived by:
            World Data Center for Geomagnetism
            DTU Space, National Space Institute,
            DK-2800 Kgs. Lyngby, DENMARK

Southern PC-index (1 min PCS) is derived by:
            Department of Geophysics
            Arctic and Antarctic Research Institute
            Bering Street 38, St. Petersburg, 199226
            RUSSIA