1. Marshall, N. B., “Aspects of Deep Sea Biology” (Hutchinson, London, 1954).
2. Beebe, W., “Half Mile Down” (John Lane, The Bodley Head, London, 1935).
3. Walker, M. A., J. Physiol. Proc., [133, 56P (1956)].
4. Denton, E. J., J. Physiol. Proc., [133, 56–57P (1956)].
5. Jerlov, N. G., Reports of the Swedish Deep Sea Expedition, 3, Physics and Chemistry, Fasc. 1 (1947–48).