1. 1) Hildebrandt G, Hanke O, Engelbertz P. Tagesschwankungen im EKG. Die Medizinische 1954; 8: 1414-6.
2. 2) Berges D. Untersuchungen über das Ausmaβ von Tagesschwankungen im EKG gesunder Versuchspersonen. Z Kreislaufforschung 1965; 54: 35-49.
3. 3) Smolensky MH, Tatar SE, Bergman SA, et al. Circadian rhythmic aspects of human cardiovascular function: a review by chronobiologic statistical methods. Chronobiologia 1976; 3: 337-71.
4. 4) Verveat P, Amery W. Reproducibility of QTc-measurements in healthy volunteers. Acta Cardiol 1993; 48: 555-94.
5. 5) Smolensky MH, Bergman SA, Barnard CN, Beck W, Kraft IA. Circadian rhythmic aspects of innervated and non-innervated cardiac tissue of single- and double heart-transplant patients. Cardiovasc Dis Bull Tex Heart Inst 1976; 3: 150-68.