Mertens, R., Kegels, G., Stroobant, A., Reybrouck, G., Lamotte, JM., Potvliege, C., Vancasteren, V., Lauwers, S., Verschraegen, G., Wauters, G., Minne, A., & Thiers, G. (1987). The National Prevalence Survey of Nosocomial Infections in Belgium, 1984. Journal of Hospital Infection, 9(3), 219-229. https://doi.org/10.1016/0195-6701(87)90117-4 (Original work published 1987)