Tarazona-Manrique, Luis Edgar, Roy José Andrade-Becerra, and Julio César Vargas-Abella. “Variation of Milk Urea Nitrogen According to Milk Yield and Milk Protein in Holstein Cows in Boyacá, Colombia”. Revista de Investigaciones Veterinarias del Perú 34, no. 2 (April 28, 2023): e23668. Accessed August 17, 2024. https://revistasinvestigacion.unmsm.edu.pe/index.php/veterinaria/article/view/23668.