(1989). Proceedings of the 40th North Central Avian Disease Conference and Poultry Respiratory Disease Symposium, 1989. [Minneapolis, MN?]: College of Veterinary Medicine, Minnesota Extension Service, University of Minnesota.

Proceedings of the 40th North Central Avian Disease Conference and Poultry Respiratory Disease Symposium, 1989. [Minneapolis, MN?]: College of Veterinary Medicine, Minnesota Extension Service, University of Minnesota, 1989.

Proceedings of the 40th North Central Avian Disease Conference and Poultry Respiratory Disease Symposium, 1989. [Minneapolis, MN?]: College of Veterinary Medicine, Minnesota Extension Service, University of Minnesota, 1989.