1. 1. T. Lewis : Mechanism and Graphic Registration of the Heart Beat , 3rd edition , Shaw and Sons, London. 1925 , p.229 .
2. 2. S. Bellet : Clinical Disorders of the Heart Beat , 2nd edition , Lea and Febigcr, Philadelphia, 1963 p.1061 , andChapters9. 13 and14.
3. Aberrant Ventricular Conduction of Escaped Beats
4. The U wave and aberrant intraventricular conduction