A. Forsgren, K. Riesbeck, und H. Janson. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 46 (5):
726--731(März 2008)PMID: 18230042.
M. Breukels, E. van der Zijde, M. van Tol, und G. Rijkers. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 34 (2):
191--7(Januar 2002)PMID: 11740707.
WHO. Relevé Épidémiologique Hebdomadaire / Section D'hygiène Du Secrétariat De La Société Des Nations = Weekly Epidemiological Record / Health Section of the Secretariat of the League of Nations, 82 (10):
79--87(März 2007)PMID: 17348094.
R. Tsang, M. Sill, S. Skinner, D. Law, J. Zhou, und J. Wylie. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 44 (12):
1611--4(Juni 2007)PMID: 17516405.