GALLO, C., C. TEUBER, M. CARTES, H. URIBE, and T. GRANDIN. “Improvements in Stunning of Cattle With a Pneumatic Stunner After Changes in Equipment and Employee Training”. Archivos De Medicina Veterinaria, vol. 35, no. 2, Dec. 2003, pp. 159-70, doi:10.4067/S0301-732X2003000200004.