Depending on what you are looking for, here are the most relevant articles related to that specific value: Medical & Health Research
, which defines the upper limit of normal heart rate values in their large cohort study. Depending on what you are looking for, here
: Research on PMC investigating natural menopause and stroke risk notes that the statistical power of their study was 97.7% ( Technical & Statistical Reports Depending on what you are looking for, here
: An article on PMC discusses how body size influences heart rate in children. It uses 97.7% as a threshold for a +2positive 2 Depending on what you are looking for, here