%0 Journal Article %T Alfvén waves: To the 80th anniversary of discovery %A Guglielmi, A.V. %A Klain, B.I. %A Potapov, A.S. %K Alfvén velocity, dispersion law, group velocity, geometrical optics, heavy ions %J Solar-Terrestrial Physics %D 2022 %N 8 %P 1 %I INFRA-M Academic Publishing LLC.