1. Heart Sounds and Murmurs: A Clinical and Phonocardiographic Study;Ongley,1960
2. Auscultation of the Heart and Phonocardiography;Leatham,1975
3. Acoustical performance of the stethoscope: a comparative analysis;Kindig;Am Heart J,1982
4. The effects of tubing bore on stethoscope efficiency;Rappaport;Am Heart J,1951
5. Auscultation of the Heart;Ravin,1977