Esteban-Garrido, E., Hernández-Núñez, A., Echeverría-García, B., Rojas-Farías, F. and Borbujo, J. (2019) “Ultrasound appearance of a sucking knuckle pad. An update.”, European Journal of Pediatric Dermatology, 29(1), pp. 20-22. doi: 10.26326/2281-9649.29.1.1943.