1. Creer, K. M., Phil. Trans. Roy. Soc., A, 250, 111 (1957).
2. Irving, E., Palaeomagnetism (John Wiley and Son Ltd., 1964).
3. Stubbs, P. H. S., thesis, Univ. of London (1958).
4. Creer, K. M., in Problems in Palaeoclimatology, 269 (Interscience, 1964).
5. Chamalaun, F. H., and Creer, K. M., Nature, 198, 375 (1963).