1. Kornelissen Zh., Khalberg F., Breus T.K., Vatanabe I., Sotern R.B., Khaus E. et al. On the problem of origin of biologic week on the basis of variations of a rhythm of heart rate in humans in the cycle of solar activity. Biofizika. 1998; 43(4): 666—9. (in Russian)
2. Breus T.K., Obridko V.N., Khalberg F. On the problem of origin of the biological week. In: SB. works of the International scientificmethodical conference «Ancient astronomy, Sky and man.» 19—24 November 1997. Moscow; 1998: 38. (in Russian)
3. Hildebrand G., Band-Reges I. Chronobiologie in der aturheilkunde: Grundlagen der Circaseptanperiodik. Haug. Heidelberg, 1992: 102.
4. Aveni A.F. Empires and Time: Calendars, Clocks and Cultures. New York: Basic books Inc. 1989.
5. Young M. The Metronomic Society: Natural rhythms and human timetable. Cambridge Massachusetts: Harvard University Press; 1988.