S. Baker, and G. Dougan. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, (July 2007)PMID: 17582565.
S. Berrón, L. Fuente, E. Martín, and J. Vázquez. European Journal of Clinical Microbiology & Infectious Diseases: Official Publication of the European Society of Clinical Microbiology, 17 (2):
85--89(February 1998)PMID: 9629971.
J. Bigham, M. Hutcheon, D. Patrick, and A. Pollard. Canada Communicable Disease Report = Relevé Des Maladies Transmissibles Au Canada, 27 (2):
13--8(January 2001)PMID: 11227821.