Rogers, Karen C., Thomas A. Portillo, Dennis E. Smialek, Del G. Miles, Terry W. Lehenbauer, and Russell Smyth. 2008. “A Comparison of Two Mannheimia Haemolytica Vaccination Strategies in Freshly Weaned Southeastern Feedlot Heifers”. The Bovine Practitioner 43 (1):27-31. https://doi.org/10.21423/bovine-vol43no1p27-31.