1. E. Longin, T. Schaible, T. Lenz, S. Konig, (2005). “Short term heart rate variability in healthy neonates: normative data and physiological observations”, Early Human Development, 81, pp.663–71.
2. Task Force of the Euro. Soc. of Cardiol., the North Amer. Soc. of Pacing and Electrophysiol., (1996). “Heart rate variability: standards of measurement, physiological interpretation and clinical use”, Circulation, 93, pp. 1043–65.
3. B. Boashash, (2003) Time-Frequency Signal Analysis and Processing: A Comprehensive Reference, Elsevier, Oxford.
4. J. Villa, F. Palacios, J. Presedo, M. Fernandez-Deigado, P. Felix, S. Barro. (1997): “Time-frequency analysis of heart-rate variability: an improved method for monitoring and diagnosing myocardial ischemia”, IEEE Eng. in Med. and Biol., pp.119–126.
5. H. G van Steenis, W. L. J. Matens, J. H. M. Tulen. (2002). “Timefrequency parameters of heart rate variability: using instantaneous amplitude and frequency to unravel the dynamics of cardiovascular control process”, IEEE Eng. in Med. and Biol., pp.46–58.