1. Animal Health Service Institute. 1991. Annual Report. Anim. Health Service Inst., Zwolle, The Netherlands.
2. Management of dry cows to reduce mastitis;Eberhart;J. Dairy Sci.,1986
3. Laboratory Methods for Use in Mastitis Work. Document No. 132,1981
4. Epidemiologic Research, Principles and Quantitative Methods;Kleinbaum,1982
5. Resistance mechanism of the bovine udder. New implications for mastitis control at the teat end;Nickerson;J. Am. Vet. Med. Assoc.,1987