L. Chui, T. Chiu, J. Kakulphimp, and G. Tyrrell. Clinical Microbiology and Infection: The Official Publication of the European Society of Clinical Microbiology and Infectious Diseases, 14 (5):
473--479(May 2008)PMID: 18294244.
S. Berrón, L. Fuente, E. Martín, and J. Vázquez. European Journal of Clinical Microbiology & Infectious Diseases: Official Publication of the European Society of Clinical Microbiology, 17 (2):
85--89(February 1998)PMID: 9629971.