García del Blanco N, Gutiérrez C B, de la Puente V A, Rodríguez Ferri E F
Section of Microbiology and Immunology, Department of Animal Health, Faculty of Veterinary Medicine, University of León, 24007 Léon, Spain.
Vet Rec. 2004 Jan 10;154(2):55-6. doi: 10.1136/vr.154.2.55.