TY  - RPRT
TI  - Improved phonocardiogram system based on acoustic impedance matching.
AU  - R S Schwartz
AU  - J T Reeves
AU  - I E Sodal
AU  - F S Barnes
PY  - 1980
DO  - 10.1152/ajpheart.1980.238.4.h604
UR  - https://pubmed.ncbi.nlm.nih.gov/7377335/
ID  - 7377335
ER  -