1. Adolph, E. F.: Ranges of heart rates and their regulations at various ages (rat). Am. J. Physiol.212, 595?602 (1967)
2. Åstrand, I.: Aerobic work capacity in men and women with special reference to age. Acta Physiol. Scand.49, suppl. 169 (1960)
3. Barnett, S. A., Spencer, M. M.: Feeding social behaviour and interspecific competition in wild rats. Behaviour3, 229?242 (1951)
4. Belanger, D., Tetreau, B.: L'influence d'une motivation inappropriée sur le comportement du rat et sa fréquence cardiaque. Canad. J. Physiol.15, 6?14 (1961)
5. Berg, B. N., Hamison, C. R.: Blood pressure and heart size in aging rats. J. Gerontol.10, 416?419 (1955)