Hernández Ramírez, Iván, and Rubén Dario Manrique Hernández. “Prevalence of Down Syndrome in the Cehani-Ese in San Juan De Pasto Colombia 1998-2003”. NOVA Biomedical Sciences Journal, vol. 4, no. 5, June 2006, pp. 50-56, https://doi.org/10.22490/24629448.347.