Rogers, K.C., Portillo, T.A., Smialek, D.E., Miles, D.G., Lehenbauer, T.W. and Smyth, R. 2008. A Comparison of two Mannheimia haemolytica vaccination strategies in freshly weaned southeastern feedlot heifers. The Bovine Practitioner. 43, 1 (Dec. 2008), 27–31. DOI:https://doi.org/10.21423/bovine-vol43no1p27-31.