A nosocomial outbreak of influenza during a period without influenza epidemic activity
J.P. Horcajada, T. Pumarola, J.A. Martínez, G. Tapias, J.M. Bayas, M. de la Prada, F. García, C. Codina, J.M. Gatell, M.T. Jiménez de Anta
European Respiratory Journal 2003 21: 303-307; DOI: 10.1183/09031936.03.00040503