1. Reindell, H., Klepzig, H., Stein, H., et al., Herz-Kreislaufkrankheiten und Sport, Munchen, 1960.
2. Venerando, A., Electrocardiography in Sports Medicine, J. Sports Med., 1979, vol. 19, p. 107.
3. Letunov, S.P. and Motylyanskaya, R.E., Vrachebnyi kontrol’ v fizicheskom vospitanii (Medical Control in Physical Education), Moscow: Fizkul’tura i Sport, 1951.
4. Dembo, A.G., Syndrome of Left Ventricular Overload in Healthy Subjects, Kardiologiya, 1962, issue 3, C. 70.
5. Butchenko, L.A., Electrocardiography in Sports Medicine, Leningrad: Medgiz, 1963.