Costa Monteiro, S., L. Correia-Costa, and E. Proença. “Perfusion Index in Preterm Newborns: Predictive Value for Morbimortality and Association With Apgar Score at Five Minutes and CRIB-II Score”. Journal of Pediatric and Neonatal Individualized Medicine (JPNIM), vol. 8, no. 1, Jan. 2019, p. e080104, doi:10.7363/080104.