1. Scheich, H., Langner, G., Tidemann, C., Coles, R. B. & Guppy, A. Nature 319, 401–402 (1986).
2. Andres, K. H. & Von Düring, M. in Sensory Receptor Mechanisms (eds Hamann, W. & Iggo, A.) 81–89 (World Science, Singapore, 1984).
3. Kalmijn, A. J. in Handbook of Sensory Physiology Vol. III/3 (ed. Fessard, A.) 147–200 (Springer, Berlin, 1974).