ICRC · 1990 · 10 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsGalactic AstronomySolar AstronomyGalactic NucleiActive Galactic Nuclei ContributionActive Galactic Nuclei Ultraviolet EmissionActive Galactic Nuclei VariabilityActive Galactic Nucleus ContributionCosmic-ray CompositionCosmic-ray SpectraGalactic Cosmic RaysSolar Minimum