1. Bureau of Mineral Resources, Geology and Geophysics, Report No. 56, Magnetic Results from Toolangi Observatory, Victoria, 1955?1958, by,C. A. van der Waal andR. M. Sorenson (1960).
2. S. Chapman,The Earth's Magnetism, Methuen35 (1951).
3. S. Chapman andJ. Bartels,Geomagnetism, Oxford. (a) Vol. 2, 561, (b) Vol. 2, 547, (c) Vol. 2, 582 et seq. (1940).
4. S. Chapman andJ. C. P. Miller,The Statistical Determination of the Lunar Daily Variations in Geomagnetic and Meteorological Elements, Roy. Astron. Soc. Mon. Not., Geophys., Suppl.4, (1940), 649.
5. G. Goertzel,An algorithm for the evaluation of finite Trigonometric series, Amer. Math. Monthly65 (1958), 34.