1. Beat-to-beat and observer variation of the electrocardiogram;Fischmann;Amer. Heart J.,1968
2. Digital recording of electrocardiographic data for analysis by a digital computer;Taback;IEEE Trans. Biomed. Engin.,1959
3. Automatic recognition of electrocardiographic waves by digital computer;Stallmann;Circ. Res.,1961
4. Normal electrocardiogram;Kossmann;Circulation,1953
5. Observer error and variation in interpretation of electrocardiograms in epidemiological study of coronary heart disease;Acheson;Brit. J. Prev. Soc. Med.,1960