1. Webster W. Antibiotics: use, misuse, resistance, growth promotion and non-antibiotic promotors. In: Proc. No. 95. Post Graduate Foundation, Faculty of Veterinary Science, University of Sydney, Sydney, Australia, 1987. p. 229–42
2. Epidemiology of drug resistance: implications for a postantimicrobial era;Cohen;Science,1992
3. Apparent reinfection of enzootic pneumonia-free herds: search for possible causes;Goodwin;Vet Rec,1985
4. Risk factors for the reinfection of specific pathogen-free pig breeding herds with enzootic pneumonia;Stärk;Vet Rec,1992
5. Maes D, Deluyker H, Verdonck M, Castryck F, Miry C, Vrijens B, de Kruif A. Risk indicators for the seroprevalence of Mycoplasma hyopneumoniae in slaughter pigs from farrow to finish pig herds. In: Proc. 8th ISVEE Congress Paris. France, 1997. 05.29.1