AUTHOR=Billman George E. , Huikuri Heikki V. , Sacha Jerzy , Trimmel Karin 

TITLE=An introduction to heart rate variability: methodological considerations and clinical applications

JOURNAL=Frontiers in Physiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2015.00055

DOI=10.3389/fphys.2015.00055

ISSN=1664-042X