1. 2. PW Macfarlane, and TD Vetch Lawrie . Comprehensive Electrocardiology . New York, Pergamon Press, 1989 , p. 451 .
2. 3. B Surawicz . Electrophysiologic Basis of ECG and Cardiac Arrhythmias . Baltimore, Williams & Wilkins, 1995 , p. 191 .
3. 4. DM Mirvis .Electrocardiography. A Physiologic Approach. Mosby, St. Louis, 1993 , pp. 102 , 102 , 102 .
4. 5. GS Wagner . Marriott's Practical Electrocardiography , 9th Ed . Baltimore, Williams & Wilkins, 1994 , pp. 13 , 13 , 13 , 13 , 13 , 13 , 13 .