Sarwono, E., D. S., O.-M. M, O. H., and D. G. J. “Umbilical Cord : Factors Which Influence the Separation Time”. Paediatrica Indonesiana, Vol. 31, no. 7-8, Feb. 2019, pp. 179-84, https://paediatricaindonesiana.org/index.php/paediatrica-indonesiana/article/view/2134.