A survey of remote optical photoplethysmographic imaging methods. - Daniel J. McDuff; Justin R. Estepp; Alyssa M. Piasecki; Ethan B. Blackford (EMBC, 2015)

Measuring pulse rate variability using long-range, non-contact imaging photoplethysmography. - Ethan B. Blackford; Alyssa M. Piasecki; Justin R. Estepp (EMBC, 2016)