TY  - RPRT
TI  - An accurate lead system for spatial vectorcardiography.
AU  - R A HELM
PY  - 1957
DO  - 10.1016/0002-8703(57)90176-x
UR  - https://pubmed.ncbi.nlm.nih.gov/13402701/
ID  - 13402701
ER  -