Morter, R.L. and Amstutz, H.E. 1999. Evaluating the Efficacy of a Haemophilus Somnus Bacterin in a Controlled Field Trial. The Bovine Practitioner. 1983, 18 (Jan. 1999), 82–83. DOI:https://doi.org/10.21423/bovine-vol1983no18p82-83.