1. The search for intelligent quantitation in echocardiography: “Eyeball,” “trackball” and beyond;Foster;J Am Coll Cardiol,1993
2. Analysis of interinstitutional observer agreement in interpretation of dobutamine stress echocardiograms;Hoffman;J Am Coll Cardiol,1996
3. Physics and instrumentation;Feigenbaum,2005
4. Echocardiography: Physics and instrumentation;Geiser,1996
5. Physical principles of ultrasound;Weyman,1994