National surveillance of pandemic influenza A(H1N1) infection-related admissions to intensive care units during the 2009–10 winter peak in Denmark: two complementary approaches
Gubbels , S and Perner , A and Valentiner-Branth , P and Mølbak, K, Eurosurveillance, 15, 19743 (2010), https://doi.org/10.2807/ese.15.49.19743-en