1. Alfvén, H.: In: Cosmical Electrodynamics, Clarendon, Oxford (1950a), pp. 82–84
2. Alfvén, H.: Tellus 2, 74 (1950b)
3. Alfvén, H., Fälthammar, C.-G.: Cosmical Electrodynamics, 2nd edn., pp. 100–104, 117–119. Clarendon, Oxford (1963)
4. Arthur, S.J., Henney, W.J., Mellema, G., De Colle, F., Vázquez-Semadeni, E.: Mon. Not. R. Astron. Soc. 414, 1747 (2011)
5. Babcock, H.W.: Astrophys. J. 133, 572 (1961)