1. Adushkin VV, Zetser YuI, Gavrilov BG, Sanina IA, Spivak AA (2005) The Mikhnevo observatory measuring system of geophysical fields and processes of the interaction of geospheres, in Dinamicheskie protsessy v sisteme vnutrennikh i vneshnikh vzaimodeistvuyushchikh geosfer (Dynamical Processes in the System of Inner and Outer Interactions of Geospheres). GEOS, Moscow, 13–18
2. Butcher EC, Brown GM (1981) The variability of Sq(H) on normal quiet days. The Geophys J R Astronomical Soc 64(2):527–537
3. Campbell WH (1976) An analysis of the spectra of geomagnetic variations having periods from 5 min to 4 hours. J Geophys Res 81(7):1369–1390
4. Campbell WH (1989a) The regular geomagnetic-field variations during quiet solar conditions. In: Jacobs J (ed) Geomagnetism, vol 3. Academic Press, San Diego, Calif, USA, pp 386–460
5. Campbell WH (1989b) An introduction to quiet daily geomagnetic fields. Pure Appl Geophys 131:315–331