A. Forsgren, K. Riesbeck, and H. Janson. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 46 (5):
726--731(March 2008)PMID: 18230042.
K. Hansen, and D. Singer. Pediatric and Developmental Pathology: The Official Journal of the Society for Pediatric Pathology and the Paediatric Pathology Society, 4 (2):
105--121(April 2001)PMID: 11178626.
J. Smith, N. Smith, M. O'Rourke, and B. Spratt. Proceedings of the National Academy of Sciences of the United States of America, 90 (10):
4384--8(May 1993)PMID: 8506277.