1. Anderson, D. L. (1989) Theory of the Earth. Blackwell Science Pub., Oxford, 366 pp.
2. Bloxham, J., Gubbins, D. and Jackson, A. (1989) Geomagnetic secular variation. Phil. Trans. R. Soc. A329, 415–502.
3. Brunt, D. (1941) Physical and Dynamical Meteorology. Cambridge University Press, London, 428 pp.
4. Cathles, L. M. (1975) The Viscosity of the Earth’s Mantle. Princeton University Press, Princeton.
5. Collinson, D. W. and Runcorn, S. K. (1960) Polar wandering and continental drift: evidence from palaeomagnetic observations in the United States. Bull. Geol. Soc. Amer. 71, 915–958.