A brief history of Physical Diagnosis through Auenbrugger and Laennec by Eric Rackow.
Rene Laennec's description of how he Invented and Designed the Stethoscope.
Nicholas Comins' article describing his new stethoscope and the first known idea for a binaural stethoscope.
"Self-Adjusting Stethoscope of Dr. Cammann." The original discussion of Cammann's binaural from 1855.
"The Essentials of a Good Stethoscope", by Charles Denison, A.M., M.D., October 22, 1892.
"An Historical Sketch of the Stethoscope", by D. M. Cammann, M.D., April 24, 1886.
"The Differences Between Flexible Monaural Stethosocpes and Conversation Tubes", by Erik Soiferman and Eric Rackow.
A brief history of the Practice of Percussion, by Erik Soiferman and Eric Rackow.