Szumilas, M., and M. Wielemborek. “Echo State Network-Based Estimation of Photoplethysmography Sensor-To-Skin Contact Force”. Acta Physica Polonica A ISSN 1898-794X , vol. 146, no. 4, Nov. 2024, p. 369, https://doi.org/10.12693/APhysPolA.146.369.