1. Aschoff, J. (1965). Circadian clocks. North Holland, Amsterdam
2. Bünning, E. (1973). The physiological clock. 3rd ed. English Universities Press, London
3. Chandrashekaran, M. K. (1965). Persistent tidal and diurnal rhythm of locomotor activity and oxygen consumption in Emerita asiatica. Z. vergl. Physiol. 50: 137?150
4. Chovnick, A. (1960). Biological clocks. Waverley, Baltimore, Maryland
5. Cloudsley-Thompson, J. L. (1961). Rhythmic activity in animal physiology and behavior. Academic Press, New York