Krisztalovics K, Szabó E, Danielisz A, Borbás K, Pászti J, Papp E Nagyné
National Centre for Epidemiology, Department of Communicable Disease Epidemiology, Budapest, Hungary.
Euro Surveill. 2007 Aug 16;12(8):E070816.2. doi: 10.2807/esw.12.33.03250-en.