TY  - RPRT
TI  - Letter: Concealed ventricular extrasystoles.
AU  - P R Lightfoot
PY  - 1975
DO  - 10.1016/0002-9149(75)90096-x
UR  - https://pubmed.ncbi.nlm.nih.gov/53995/
ID  - 53995
ER  -