1. Achong, A., Stahl, P. A., and Nyack, C.: 1983, Solar Phys. 88, 137.
2. Coffey, H.: 1980?81, Solar Geophysical Data, Part I, 1980?81, U.S. Dept. of Commerce, Boulder, Colorado.
3. Giovanelli, R. G.: 1939, Astrophys. J. 89, 555.
4. Greatrix, G. R.: 1963, Monthly Notices Roy. Astron. Soc. 126, 132.
5. Jeffreys, H.: 1961, The Theory of Probability, Clarendon Press, Oxford, p. 320.