1. Stark, L., “Nyquist Stability Criterion and Oscillations of a Biological Servomechanism. Selected papers in Biophysics” (in the press).
2. Campbell, F. W., and Whiteside, T. C. D., Brit. J. Ophthal., 19, 180 (1950).
3. Stark, L., and Cornsweet, T. N., Science, 127, 588 (1958).
4. Stark, L., and Sherman, P. M., J. Neurophysiol., 20, 17 (1957).
5. Campbell, F. W., and Robson, J. G. (unpublished experiments).