Azrak E, Kern M J, Bach R G, Donohue T J
Department of Internal Medicine, Saint Louis University Health Sciences Center, Missouri 63110, USA.
Cathet Cardiovasc Diagn. 1998 Sep;45(1):70-5. doi: 10.1002/(sici)1097-0304(199809)45:1<70::aid-ccd17>3.0.co;2-p.