Hammill SC, Tchou PJ, Kienzle MG, Haisty WK, Ozawa Y, Underwood DA. Establishment of signal-averaged electrocardiographic criteria with Frank XYZ leads and spectral filter used alone and in combination with ejection fraction to predict inducible ventricular tachycardia in coronary artery disease. Am J Cardiol. 1992 Aug 01; 70(3):316-20.