1. Deacon, G. E. B., Occasional Publications of The Challenger Society, No. 1 (1946).
2. Barber, N. F., and Ursell, F., Nature, 159, 205 (1947).
3. Linke, F., Ergeb. kônig. Geo. wiss, Göttingen, Math. Phys. Klasse, 7 (1909).
4. Bernard, P., C.R., 205, 163 (1937).
5. Leet, L. D., Beitr. z. Geophys., 42, 232 (1934).