1. Aschoff, J., Klotter, K., Wever, R., in: Circadian Clocks, p. XI (ed. J. Aschoff. Amsterdam: North-Holland 1965.
2. Aschoff, J.: ibid.. p. 262.
3. Aschoff, J., et al.: Oikos Suppl.13, 91 (1970).
4. Hoffmann, K.: Oecologia3, 184 (1969).
5. Wever, R.:, p. 47.