Recommendations for standardization of leads and of specifications for instruments in electrocardiography and vectorcardiography - Pipberger, HV; Arzbaecher, RC; Berson, AS; Briller, SA; Brody, DA; Flowers, NC; Geselowitz, DB; Lepeschkin, E; Oliver, GC; Schmitt, OH; Spach, M (Circulation, 1975)