Julio César Vargas Abella, Roy José Andrade Becerra, Luis Edgar Tarazona Manrique. 2020. “Prevalence of Gastrointestinal Parasites in Crossbred Sheep Diagnosed at Different Altitudes in the Highland Boyacá-Colombia”. Revista Electronica De Veterinaria, June, 38 - 49. http://veterinaria.org/index.php/REDVET/article/view/36.