1. An introduction to the use of the stethoscope;Stokes,1825
2. Perspectives in physiological monitoring;Geddes;Med Instrument,1976
3. The principles and practice of medicine;Osler,1892
4. Continuous noninvasive monitoring of respiratory rate in critically ill patients;Krieger;Chest,1986
5. Routine measurement of respiratory rate: An expensive tribute to tradition;Kory;JAMA,1957