TY  - RPRT
TI  - A wide-range linear beat-by-beat cardiotachometer
AU  - Caldwell, W. M.
AU  - Smith, L. D.
AU  - Wilson, M. F.
PY  - 1970
UR  - https://ntrs.nasa.gov/citations/19710029545
ID  - 19710029545
ER  -