J. Winstead, D. McKinsey, S. Tasker, M. Groote, и L. Baddour. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 30 (1):
87--94(января 2000)PMID: 10619738.
J. Bigham, M. Hutcheon, D. Patrick, и A. Pollard. Canada Communicable Disease Report = Relevé Des Maladies Transmissibles Au Canada, 27 (2):
13--8(января 2001)PMID: 11227821.