Cutrone, M., A. Milano, and E. Bonifazi. “Skin Disorders of the Umbilicus”. European Journal of Pediatric Dermatology 14, no. 2 (June 30, 2004): 2004. Accessed September 12, 2026. https://ejpd.migration.pkpps03.publicknowledgeproject.org/index.php/journal/article/view/291.