Checkley, S. L., Campbell, J. R., Waldner, C. L., Dowling, P. M., & Chirino-Trejo, M. (2010). A retrospective diagnostic laboratory survey of antimicrobial resistance in fecal Escherichia coli isolated from spring calves in western Canada. Canadian Veterinary Medical Association.

Checkley, Sylvia L., John R. Campbell, Cheryl L. Waldner, Patricia M. Dowling, a Manuel Chirino-Trejo. A Retrospective Diagnostic Laboratory Survey of Antimicrobial Resistance in Fecal Escherichia Coli Isolated From Spring Calves in Western Canada. Canadian Veterinary Medical Association, 2010.

Checkley, Sylvia L., et al. A Retrospective Diagnostic Laboratory Survey of Antimicrobial Resistance in Fecal Escherichia Coli Isolated From Spring Calves in Western Canada. Canadian Veterinary Medical Association, 2010.