Guerrero-Torija, A., M. Vallejo-Ruiz, A. Hernández-Núñez, and J. Borbujo. “Idiopathic Frontal Hyperpigmentation.”. European Journal of Pediatric Dermatology, vol. 30, no. 4, Dec. 2020, pp. 216-20, doi:10.26326/2281-9649.30.4.2167.