TY  - RPRT
TI  - Combined exercise echocardiography.
AU  - S N Berberich
AU  - J R Zager
PY  - 1981
DO  - 10.1378/chest.80.3.336
UR  - https://pubmed.ncbi.nlm.nih.gov/7273889/
ID  - 7273889
ER  -