S. Botman and  D. Borchevkin and  V. Petrov and  E. Bogdanov and  M. Patrushev and  N. Shusharina,  Photoplethysmography-Based Device Designing for Cardiovascular System Diagnostics.   journal   = {International Journal of Biomedical and Biological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2015, vol. 105(9). 689 - 693
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/10002239.