M. Domeika, A. Savicheva, E. Sokolovskiy, R. Ballard, and M. Unemo. Euro Surveillance: Bulletin Européen Sur Les Maladies Transmissibles = European Communicable Disease Bulletin, 12 (12):
E071206.3(December 2007)PMID: 18067849.
E. Koumans, R. Johnson, J. Knapp, and M. Louis. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 27 (5):
1171--1180(November 1998)PMID: 9827265.