1. Heart sounds and murmurs. Clinical and phonocardiographic study;Ongley,1960
2. From auscultation to phonocardiography;Luisada,1965
3. Speech and hearing;Fletcher,1929
4. The fourth heart sound;Tavel;Circulation,1974
5. On experts and expertise: The effects of variability in observer performance;Spodick;Am. J. Cardiol.,1975