Geomagnetic indices k and c, 1952
Bartels, J
Geomagnetic indices k and c, 1952 J. Bartels and J Veldkemp - Washington 1954
Geomagnetic indices
083.550.38 / IATME-12G
Geomagnetic indices k and c, 1952 J. Bartels and J Veldkemp - Washington 1954
Geomagnetic indices
083.550.38 / IATME-12G