@inbook{1162724866,
author={Kim E. Barrett and Susan M. Barman and Heddwen L. Brooks and Jason X.-J. Yuan},
title={Origin of the Heartbeat & the Electrical Activity of the Heart},
booktitle={Ganong's Review of Medical Physiology, 26e},
publisher={McGraw-Hill Education},
address={New York, NY},
year={2019},
url={accessmedicine.mhmedical.com/content.aspx?aid=1162724866}
}