1. The enigma of herd: a comparison of different models to account for group effects in multivariable analysis;Curtis,1988
2. Herd-level risk factors for Staphylococcus aureus and Streptococcus agalactiae intramammary infections;Dargent-Molina;Prev. Vet. Med.,1988
3. Epidemiologic Research;Kleinbaum,1982
4. Veterinary Epidemiology;Martin,1987
5. Theoretical Epidemiology;Miettinen,1985