M. de J. Marichal, A. I. Trujillo, M. H. Guerra, M. Carriquiry, and L. Piaggio, “Comparison of kinetics of in vitro N-NH3 production and rumen degradation of N of coated urea, urea and agro industrial by products”, Agrocienc Urug, vol. 13, no. 2, pp. 52–59, Dec. 2009.