Geomagnetic indices K and C, 1955
Butels, J.
Geomagnetic indices K and C, 1955 J. Bartels, A.Romana and J. Veldkamp - Holland 1957
Geomagnetic Indices
083.550.38 / IAGA-12K
Geomagnetic indices K and C, 1955 J. Bartels, A.Romana and J. Veldkamp - Holland 1957
Geomagnetic Indices
083.550.38 / IAGA-12K