Qawqzeh, Y., Kayed, L., Otoom, M., Alharbi, M. and Khan, F.A. 2016. The Investigating of Photoplethysmogram Waveform Amplitude Changes: Aging and Atherosclerosis. International Journal of Sciences: Basic and Applied Research (IJSBAR). 30, 3 (Nov. 2016), 126–133.