Checkley, S. L., Campbell, J. R., Chirino-Trejo, M., Janzen, E. D., & Waldner, C. L. (2010). Associations between antimicrobial use and the prevalence of antimicrobial resistance in fecal Escherichia coli from feedlot cattle in western Canada. Canadian Veterinary Medical Association.

Checkley, Sylvia L., John R. Campbell, Manuel Chirino-Trejo, Eugene D. Janzen, and Cheryl L. Waldner. Associations between Antimicrobial Use and the Prevalence of Antimicrobial Resistance in Fecal Escherichia Coli From Feedlot Cattle in Western Canada. Canadian Veterinary Medical Association, 2010.

Checkley, Sylvia L., et al. Associations between Antimicrobial Use and the Prevalence of Antimicrobial Resistance in Fecal Escherichia Coli From Feedlot Cattle in Western Canada. Canadian Veterinary Medical Association, 2010.