1. Marriott HJL, Practical Electrocardiography, 7th ed., Baltimore: Williams & Wilkins, 1983:373–400.
2. American Heart Association Committee on Electrocardiography. Recommendations for standardization of leads and specifications for instruments in electrocardiography and vectorcardiography. Circulation 52:11–31, 1975.
3. International Electrotechnical Commission. Draft standard specification for the performance of single and multi-channel electrocardiographs. IEC document 62D (Central Office) 6, 1978.
4. Berson AS, Pipberger HV. The low-freuqency response of electrocardiographs, a frequent source of recording errors. Am Heart J 71:779–789, 1966.
5. Gallino A, Chierchia S, Smith G, Croom M, Morgan M, Marchesi C, Maseri A. Computer system for analysis of ST segment changes on 24 hour Holter monitor tapes: comparison with other available systems. J Am Coll Cardiol 4:245–252, 1984.