International disease surveillance. Quarterly report January to March 1991.
D000820:Animal Diseases / Q000453:epidemiology*; D000818:Animals; D001424:Bacterial Infections / Q000453:epidemiology / Q000662:veterinary; D004196:Disease Outbreaks / Q000662:veterinary*; D005060:Europe / Q000453:epidemiology; D014777:Virus Diseases / Q000453:epidemiology / Q000662:veterinary*