1. Akasofu, S., Chapman, S.: The enhancement of the equatorial electrojet during polar magnetic sub-storms. J. Geophys. Res. 68, 2375–2382 (1963).
2. Alldredge, L. R.: Instruments and geomagnetic stations. Physics of Geomagnetic Phenomena. (Ed. S. Matsushita and W. H. Campbell), Acad. Press pp. 29–66 (1967).
3. Ann, IGY, IV, Pt V, Geomagnetism Part II, 247–329 (1957).
4. Annexstad, J. O., Wilson, C. R.: Pc 1 fine structure phase shift at high latitude conjugate points. J. Geophys. Res. 73, 3063–3065 (1968).
5. Baransky, L. N., Kazak, B. N., Geller, L. A.: Propagation velocity of Pc 1 waves in the electromagnetic field of the Earth. Dokl. Akad. Nauk SSSR No 1, 85, 1967.