Rodríguez-Morales, Edda L., María S. Correa-Rivas, and Lillian E. Colón-Castillo. 2012. “Monocephalus Diprosopus, a Rare Form of Conjoined Twins, and Associated Congenital Anomalies”. Puerto Rico Health Sciences Journal 21 (3). https://prhsj.rcm.upr.edu/index.php/prhsj/article/view/875.