1. Winfree, A. T., Nature, 253, 315 (1975).
2. Winfree, A. T., J. comp. Physiol., 85, 105 (1973).
3. Pavlidis, T., in Lectures on Mathematics in Life Sciences, (edit. by Gerstenhaber), 88–112 (Ann. Math. Society, Providence, 1968).
4. Pavlidis, T., Biological Oscillators: Their Mathematical Analysis (Academic, New York, 1974).
5. Wever, R., in Circadian Clocks (edit. by Aschoff, J.), 47–63, and 74–83 (North Holland, Amsterdam, 1965).