Geomagnetic indices K and C, 1955
Butels, J.
Geomagnetic indices K and C, 1955 J. Bartels, A.Romana and J. Veldkamp - Holland 1961
Geomagnetic Indices
083.550.38 / IAGA-12I
Geomagnetic indices K and C, 1955 J. Bartels, A.Romana and J. Veldkamp - Holland 1961
Geomagnetic Indices
083.550.38 / IAGA-12I