Ayala Guanga, L., G. Garay Peña, F. Carpio Alemán, R. Rodas Carpio, P. Nieto Escandón, and G. Calle Ortiz. “Colloidal Centrifugation As a Method of Sperm Selection Prior to Cryopres-Ervation With Glycerol in Canines”. Revista De Producción Animal, Vol. 31, no. 1, Mar. 2019, pp. 44-54, https://revistas.reduc.edu.cu/index.php/rpa/article/view/e2684.