Publication
Euro Surveill. 2009;14(43):pii=19375. https://doi.org/10.2807/ese.14.43.19375-en
Euro Surveill. 2009;14(44):pii=19388.
Euro Surveill. 2008;13(43):pii=19015.
PLoS Med. 2008 Apr 15;5(4):e89. doi: 10.1371/journal.pmed.0050089. PMID: 18416600; PMCID: PMC2288622.