1. Ploss, R. H.. A Simple Constant Monitoring System, Anesthesiology,16: 466 (1965).
2. Littman, Nursescope Diaphragm Stethoscope; 3M Company, Medical Products Division.
3. Double coated pressure sensitive stethoscope adhesive. Seal-on-Products, A Division of Kraft Tapes Limited, 1165 Frances Street, London, Ontario.