TY  - RPRT
TI  - A SIMPLE AUDIO-CALIBRATED STETHOSCOPE.
AU  - N S BLACKMAN
PY  - 1964
DO  - 10.1001/jama.1964.03070100070022
UR  - https://pubmed.ncbi.nlm.nih.gov/14174062/
ID  - 14174062
ER  -