References
- Blackburn , H. , Taylor , H. , Okamata , N. , Raubsharjh , P. , Mitchell , P. L. and Kerkhof , A. C. 1967 . “ The standardization of the exercise ECG. A systematic comparison of chest lead configurations employed for the monitoring during exercise ” . In Physical activity and the heart , Springfield , Ill. : C. C. Thomas .
- Ellestad , M. H. 1975 . Stress testing: Principies and practice , Philadelphia : F. A. Davis Company .