P. C. Nugraha, M. R. Mak’ruf, Lusiana, S. Luthfiyah, and W. Caesarendra, “Long Distance Dual SpO2 Monitoring System for Premature Babies Using Bluetooth Communication ”, j.electron.electromedical.eng.med.inform, vol. 3, no. 2, pp. 106-110, Jul. 2021.