Casas, A. et al. 1999. Effect of the number of boluses and time of administration on ruminants’ fecal excretion pattern of chromium oxide. The Journal of Agriculture of the University of Puerto Rico. 83, 3-4 (Oct. 1999), 123–134. DOI:https://doi.org/10.46429/jaupr.v83i3-4.3883.