C. Walker, and H. Wiesenfeld. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, (April 2007)PMID: 17342664.
J. Reed, J. Thistlethwaite, and J. Huppert. The Journal of Adolescent Health: Official Publication of the Society for Adolescent Medicine, 41 (1):
14--18(July 2007)PMID: 17577529.
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.